JanDen, are you located in California?

Boulder=liberal; your version of Berkeley.
Anyway, as one of the few CMAA adherents that still advocates a role for the guitar at Mass in general, here are some off the top o' the head thoughts:
*The key word of the mandate from the pastor is "begin." Begin to use chant, begin to use polyphony, Latin....etc.
*Secondly, if you're not the director of music, but a director of only one of multiple ensembles, clarify with the DM and the pastor the extent of your personal involvement with this whole shift. And emphasize, strongly, that the shift doesn't have to be immediate or have the magnitude of a 7.5 quake/tsunami.
*If your role is only with your choir, then stick to Noel's primary assertion here and elsewhere: a RCC choir doesn't require an organist/pianist/autoharp accompanist. Work on vocal proficiency starting with all of the requisite aspects that are perfectly honed by learning the basics and graces of chant. Having seen pretty much all of the most recent (within twenty years) chant resources, I am convinced that the Simple English Propers is the most versatile and accessible "system" to introduce four lines, square notes to singers who read modern notation or not. But there are loads of other very worthy volumes, modern notation in Latin and English, etc. on main Musicasacra.com webpage "chant resources."
Whatever parish hymnal/missal "aide" is in the pews, plow through it over and over with a fine tooth comb analyzing which hymns and other pieces meet both theological and music muster as being traditional, or worthy of our sacred treasury. Compare your postive choices to the Vatican II Hymnal (a must own) for perspective. Look for modern compositions that are obviously chant inspired. Absence of stems on pieces like Barbara Bridge's WE WALK BY FAITH (OCP) are a dead giveaway. there are lots of such pieces, with stems or without. You just have to sing through them using a sort of "chant ethos." Anything mensurate, or metrical can still essentially be chanted.
If your choir isn't stable enough to hold forth SA(T)B with strophic hymnody, then I'd advise you to have your men sing the hymn melody, with the women singing either the alto part written, or better yet the tenor part, whichever seems to move closer to parallel thirds or sixths to the melody. Unless you have a soprano that actually sings like a ten year old perfectly tuned and voice English choir boy, don't ever let any diva sing a descant. Makes no sense without a great pipe organ and a seriously good singing choir and congregation.
If you do manage SATB quite easily, still no organ, absolutely invest in Richard Rice's SIMPLE CHORAL PROPERS (also found at Musicsacra.com). Methodical, emulative of Orthodox homophony, and also using a sort of faux-bourdon verse formula that will help teach singers to move the text along outside of meter while still in SATB. Priceless.
I don't want to address the issue of using the guitarists without more information on the whole program. But, political and terratorial sensibilities must be taken into account before holding some sort of plenum meeting that simply "announces" the pastor's desires and a timetable for implementation.
There are many accounts of choirs who do occasionally require accompanimental assistance with all these types of music, and where a discreet and accomplished guitarist can provide that "intonational" backbone even with chestnuts such as "Panis Angelicus" "Adoro te devote," Ave Verum Corpus (Mozart), Adoramus te Christe (Lambilotte) ad infinitum.
More later?

There are a couple of other Colorado folks here, Jan… Carl D's in Fort Collins, and I'm in Greeley.

I lost my entire music ministry (all musicians) when our new pastor came in and introduced polyphony and organ music. In order to placate everybody, I began the changes by slowly deleting guitar music and slowly introducing more organ music and Communios from Simple English Propers. However, the flutist, guitarist and pianist were highly offended that they could no longer "take over" the mass and made a large noise when they moved on (in one case a petition was even sent around to remove the pastor). These are people who I believed were highly motivated by their love of God and their desire to serve. But when push came to shove, they showed their true colors and found another parish where "we are appreciated for our talents". Last week for the Easter Vigil our former director made a visit and called me Easter Sunday to tell me everything that was "wrong" with the music.

I have no problem whatsoever with praise and worship, charistmatic music outside of the context of the mass and have encouraged these musicians (before they left) to participate in prayer services where they could share their talents in the way they feel called to serve. They did not bite at this compromise at all.

In my opinion, too many church musicians have gotten to the point where they use the mass as a forum for their own frustrated desires to be noticed and admired, rather than to engage in humble service to the people. I also agree that sometimes silence is more important than any elaborate hymns and have begun to use the period immediately following communion as a period of total submission to the Eucharist. I've also started to slowly get away from the "hymn sandwich" mentality of the past.

My experience was to be very gradual - this takes years. But even so, people will grouse. The most critical thing is the visible support of your Priest - when you push beyond that limit, you're totally exposed.

Drop me a line if you'd like to get together to a more extensive discussion, I'm in Fort Collins.

The Simple Choral Propers have different words to the entrance and communion antiphons than what are printed in the publication. Does my choir sing them anyway and the congregation doesn't have the right words (=they don't participate)?

I assume that the congregation is provided with OCP materials, which reproduce the Entrance Antiphon and Communion Antiphon from the Missal that are provided in case the Introit and Communio are spoken (by the priest) not sung (eg. from the SEP or from the Graduale). This is unfortunate, for by doing so, not only are the words frequently different, but there are no Psalm verses that would normally be sung (by cantor or choir), making it impossible for people to follow along.

If you want the congregation to participate, then either you have to provide printed text/music in some form (say, for the SEP), or have available music for the antiphon that is easily sung by rote upon hearing it sung through initially by the cantor/choir. It's not an ideal situation.

I agree that we directors need to provide our people with printed music as worship aids. But, as the old adage goes, "you can lead the horse to water...but can't make him drink it". I tried printing all the Lent ordinaries for the congregation. I recently found most of them folded like fans or untouched in the pews. It was very discouraging.

And, Frogman, nothing disturbs me more than applause. I am not there for constant praise (or criticism). Unfortunately, we are living in a world where the "feel good" mentality of everything takes precedence over everything. Our new pastor gives wonderful, thought-provoking sermons. Our masses are meant to bring us closer to the Lord, and not give us a vehicle for entertainment.

I think the mentality of many people that our priests need to be "friends" rather than shepherds hurts in many ways. I know in our parish, our former pastor golfed with many parishioners and allowed them to make all decisions in the parish (outside of the parish council). Last year I hired a band for our annual carnival and the head of the Knights of Columbus, who is also head of almost every ministry, decided he didn't like the music so he went to the pastor and complained. The pastor came to me, as director, and told me to "pay them and get rid of them". My heart broke as I "fired" the band for no reason other than one person's opinion trumped everything, and the pastor wanted to be "friends" with him. And, despite the fact that the pastor was assigned elsewhere, he continues to be friendly with many of our parishioners and even bad-mouths the new pastor. It's just been a horrible situation. And, of course, it follows through to the music.

But, like many of you have said, it takes a long, long time to reform people's mentalities with regard to this.