Just finished replacing both serpentine belts.....very easy job. Tools required are:
1. Breaker Bar
2. Ratchet with 13mm and 15 mm sockets
If you have ramps use them, if you don't ....get them!
I'm glad the Bentley manual shows how the belt goes on, cause remembering the way that belt goes around all those wheels ain't easy. The tensioner on the main belt makes everything easy.
The smaller (outer) belt requires poping off a plastic cover and loosening a bolt. I couldn't find anywhere stating a proper tension setting for the smaller belt, so I played it by ear.
Don't waste money having a shop do it, this is one job everyone can do, as easy as changing oil.