Its not that bad a job IF you have a lift,and a helper to get the tank down,and back up in place again....and the tank is near empty,which never seems to be the case when a fuel pump craps out..otherwise its no fun at all,and trying to do one lying under a truck on the ground is the pits..
If your going thru all that effort ,you may as well put a new pump and sending unit in it while it is out,even if they "might" still be good--if they have over 50K miles or 10 years,they are due...sucks that most electric pumps and sending units are well over 200 bucks by themselves--it makes it tough for the mechanic to make a decent labor rate when parts are that expensive.