Well, I always like to share fix-it tips and stuff with car forum folks.
Took off the alternator, removed the R134A, then removed the compressor. Was only 3 bolts and was able to slide it out from the bottom w/o undoing a radiator hose.
I went ahead a bought an 8oz supply of gm approved pag oil ( even though we had 2 viscoscities of pag oil already, the gm bottle had no indication of what the weight was, so we just got what was recommended by alldata). We only used 4 oz, I never could find out exactly how much was specified, but we figured 4oz was probably enough. 2 new orings for $10 each! and we reconnected the new, complete compressor/clutch assembly.
Reattached the alternator and serpentine belt( I'd just changed it out last month ), drew down the system with an a/c vaccum pump, then put the recommended amount of 134A back in.
Cold air once again!! Yea! Go have a beer or 10 now!
Called a dealer and they said in the neighborhood of $1000 to fix +/-. Labor was gonna be $450 and compressor was $550. They'd have probably nickel and dimed me to death with R134, o-rings, and misc crap for another couple o' hundred bucks. My total cost was $327... $270 for compressor, $57 for 2 O-rings and 8oz of pag oil.
Value was priceless as I got my mom ready for the upcoming brutal summer heat in deep Southeast Texas for not so much $$.
All in all, 2 bolts to remove the alternator. 3 bolts holding the compressor to the engine and 1 bolt holding the a/c lines to the compressor. If you can remove a serpentine belt, ( and have a way to remove gas from the a/c system ), you can replace a compressor. Take it to a shop to remove moisture and recharge & you're good to go.
Lastly, yesterday was a very low humidity day.... good for working on a/c as the chance to introduce moisture into the system was much less than working on a high humidity day.