Water Pump 2004 Express

How hard is it to change the water pump on a 2004 Express with a 4.3 from the top? I know changing the pump is strait forward just like any other Chevy engine. But will I need to tie a rope to my waist and have someone pull me out when I finish.

Thanks

Well I got it, the hardest thing was getting the top shroud out. I tied the AC hose and throttle cable to the wiper. Then I was able to work the right side out past the radiator.