Lucky for you it's a Suburban. The tank's behind the rear axle only on Suburbans and 2-door Tahoes, they are MUCH easier to remove than the tanks between the frame rail and driveshaft on every other truck.
To remove the fuel from the tank I like to let the pump do the work.
Start by disconnecting the fuel filter that's on the inside of the driverside frame rail under the drivers door. Remove the hardline from the filter inlet. Attach a long piece of hose from that hardline. Make the hose long enough to feed the fuel into other cars' tanks or into cans. Under the hood there is a relay for the fuel pump. If you have a piece of wire or even a jumbo papreclip, stick it into the pins that #30 and #87 on the relay plug into. That will run the fuel pump. (no need for key or iginition)
Here's a photo for reference:
http://bertok.us/pics/fuelpumprelay.jpg

Thanks so much!! so then just jack the tank down and the fuel pump should be on top of it? or in it?

In it, but accessible from the top. Use a toothbrush and compressed air to clean everything before loosening that ring, otherwise all the crap will end up inside the tank.

be sure to replace your fuel filter as well!!! Also check your fuel pump connector and make sure the ground terminal is not melted.

I put together a Word doc (with pic's) on doing this if you want it?
email me hquickatbigponddotcom

Thanks yall for all your help. howard quick, i emailed you for that word doc. thanks!