I might consider doing the hymn tune propers at first. Others here have arranged the text of the propers into metrical forms. I might start in Advent using "Creator of the Stars of Night" as the tune. You can see what the reaction is and then go from there.

When I do entrance propers, they are preludes before the hymn. The communion proper we have always done before the choir receives communion. I play, then start the hymn when the choir has received. I have never done offertory propers since too much is going on at that time and either I am busy playing or the choir is busy singing. I have never found the offertory propers to have any real significance in the OF, and they often seem unrelated to anything that's happening. Someone will get their panties in a wad over that, I am sure.

It is definitely worth downloading the Society of St Gregory's Processional as it gives a complete set (at least for England) of all* the proper texts in English, including those from GS which can be used on a seasonal basis rather than having something new each week (sometimes referred to as the Common Psalms). Check the Introduction for a description of what is available, and note that is is always permissable to use Ps.33 at Communion, which suggests one possible starting point. How to use this material depends very much on how long processions take, including time spent censing the altar (if any), etc., and on the available singers. It will also depend on whether your missal and hymnal can provide suitable music.
* other than those in the lectionary or sacramentary, of course.

This requires careful thought. Of course, none of your fellow forumites know your people, what their strong and weak musical points are, especially how they accept newness of any kind, the interplay of likes and dislikes, and on and on. It is difficult to suggest a procedure without some notion of the spiritual and intellectual dispositions of a given parish.

It is a grand plus that your pastor is behind all this. He is the one who can make it work or not. I would suggest some non-patronising catechesis to prepare the way for introducing these two (two of five in a set!) propers on a specified date.

I must say that it doesn't do much for a proper introit to use it as a 'prelude' before the hymn. This disjoints it totally from the mass, of which it is an integral part - a thing which you want your people to understand. Sing a processional hymn (if necessary) and then begin the mass with its introit.

Try very hard not to assume that there will be disgruntlement. Give you people credit and allow them to step up to where you AND FATHER want them to be. Do not act as though you are introducing something bizarre that they have never heard of. Speak to them frankly as co-members of a liturgical and worshipful journey.

Before I carry on too much, I'll stop here.

(IF, IF there is a bit of negative reaction DON'T be frightened off. Stay the course, teach, and show respect without losing firm resolve.)

A cautionary note: we've seen stories like this fairly often on the forum:

1. The pastor is gung-ho for good music and decides to change things quickly.
2. The music director implements everything as directed.
3. Dissatisfied parishioners fight back, complaining about music, starting whispering campaigns against the music director, withholding donations, using their positions on parish boards to sound off. Some complain to the bishop.
4. Under financial pressure, the pastor yields and fires the music director.

As a prudent music director, you need to slow the process down and win people over, which takes time. Of course the director should immediately stop any practices that are contrary to liturgical norms, but beyond that, go gently. Make a plan to run over a few years. It might even be smart to implement the improvements at some Masses in the weekly schedule, but not others.

my recommendation is to ease in SLOW without too much disruption to what all are used to.

On occasions where the pastor has provided some catechesis for the parish prior to changes, and where he also sings his part I have found these changes most readily accepted.

For example, prior to the implementation of the new missal translation in 2011, our pastor had been given the instruction from his bishop that the new ICEL missal chants were to be used exclusively as the Mass ordinary for one year. So... before the end of the liturgical year, over a series of weeks, the pastor explained what was happening, demonstrated some of the improvements in the language and accuracy of the new translation and gave fair warning about the upcoming change. At the same time, before Mass each week, I went over the new ordinary chants with the people, using prepared Mass ordinary handouts for the people... (we didn't yet use them at Mass).

This isn't really the same as your topic (implementation of the propers), but my point is that the people were well-prepared by the pastor before we made the change.

I also agree with the above posted comments about taking things very gradually... as Chonak mentions above, the sheep can attack sometimes (not only the music director, but the pastor, too), so take care and be gentle in the changes if possible.

That only proves that one can't predict based on parish A what will happen at parish B; or that what good or bad did or didn't happen at parishes, C, D, and E, will or will not happen inevitably at parish F. What happened with fortunate Matthew is not guaranteed to or not to happen with someone else. His advice, though, is sterling.

The lesson here is not to have one's outlook coloured, one's anticipations to be informed, by the numerous horror stories. Likewise, don't take it for granted that the happily-ever-after stories will be repeated in one's particular place.

No two parishes are alike! Know your people, cultivate your pastor's support, and proceed accordingly. Some situations will permit relatively short incubation periods. Others will require quite a long and patient gestation. Know your people and act accordingly.

Cultivate a positive and confident demeanor and stay on the high road.