Just did this the other day. The hardest part is re-attaching the y-pipe. The only way I could reach it was with a stack of wobble extensions.
The most tedious part is putting all the bolts/nuts back in for the pan. Make sure you keep them in order as you take them out, as they make no sense where they go from an outside observation. If you don't have an air ratchet to speed things up, this might be the time to invest in one for your own sanity :-)
It took me about 3.5 hours, and I have a fairly well stocked tool chest.