Need to replace the water pump on my son's 2002 Yukon Denali, how hard is it going to be to do this?

You never gave us an update on how it went with replacing the water pump in your Saturn.

Got the water pump done on the Saturn and also replaced the Supentine belt at the same time. Everything went great.

Same deal--perhaps a little easier, since access is greater on a truck. Basically, follow similar steps as I gave you for the Saturn. Good time to replace radiator and heater hoses. Have a secure step or platform to stand on.