An indy shop charging $120/hr for labor? Mind as well just bring it into the dealer for that kind of money. I had my indy did fluid change on the transmission (pan drop, filter change, refill), transfer case, and both differentials for about $600 last year.

If you decides to do it yourself, then it may take that entire 3 hours or more unless you have access to a lift. And if you don't have access to a lift, it'll be a messy job

Good luck!