I decided to change the fuel pump in a 1996 Riviera. I found out it has a access panel in the trunk to replace the fuel pump. I read you have to drain the tank before installing it. is that only if you drop the tank or is that a step taken when installing it. I have a full tank of gas so I am hoping I dont have to drain it.

You should have it down to a quarter tank or less is recommended. I just changed mine in my Ultra you will spill fuel all over if it is to much in the tank, seems like i had to push the tank down to reinstall the new pump so maybe to much fuel, would, could, overflow and you're tipping it this way and that, mine seemed to hold a cup of fuel in the upper banded area, I had a big enough plastic tub to put it in as i took it out wouldn't want to try taking it straight out the trunk area, it takes a bit to drain off watch out for fumes if your inside.
One more thing is clean it as best as you can before taking it apart, the ring is normally packed with dirt, dust,an no tellin. get picks an clean it best you can, when you start beatin on that ring your gonna have a bunch more dirt.so give your self plenty of time to get things cleaned up before you get in a time jam an dump a bunch of dirt in your tank.. Have fun an be careful.

Less gas is better. But you should be fine. Your not moving the tank. Clean everything up good.

the fuel pump assembly will hold some... id get a whole bunch of towels and completely remove the carpet. other than that you should be ok.

Update, its not the fule pump. I removed the panel and removed the wiring to the pump and replaced the fuse, Turned the key - Fuse blew even with the power disconnected from the actual fuel pump...

Any ideas now that I have ruled out the pump..

Fried relay or a chafed power supply going to ground.

I am not sure what this does or if it helps. I removed the fuel pump relay that was under the back seat and then replaced the fuse and turned the key and it didnt pop the fuse. I am hoping this helps and is progress.

next step if you dont wanna spend a couple bucks on a relay is to test it to make sure its working. the easiest way to do this is to find another relay on your car thats the same. here is a video on how to check a relay.

[YT]http://www.youtube.com/watch?v=3JB63ebFfgU[/YT]

All solved - Ended up being a bad Fuel pump relay. swapped it out and it fired up

Good to hear. I will mark as fixed.