this is the how to for the engine mount, http://www.grandprixforums.net/engine_mount.php the trans mount is on the other side and easier to change, not that the motor mount is all that hard to do.

and this is what a bad trans mount looks like and how to change it too. look for part 2 Buick Regal Transmission mount pt.1 - YouTube

i just did both, took less than 2 hours to change.

pop your hood and watch the engine as you shift it from park to drive, then to reverse, see if the engine is moving A LOT, if so the mounts are bad.