If the tank is more than half full, you're better off moving the bed back ( it'll rest on the rear tires and bumper, be careful not to bend the lower rear quarters ) You WILL need friends to help move the bed.
The tank will have sealer around the lock ring for the tank fuel module, a good brake cleaner will melt it, then you just scrape it out of the way and remove the lock ring. ( replace the whole thing, not just the pump, the fuel level sending units are known problems as well ) DO USE the new rubber seal that comes with the module asembly.
IF you opt to pull the tank, be careful loosening the tank strap bolts, the nuts they are threaded into are " Speed nuts" aka a clip with threads, and they break, and then spin, and are PITA to remove when that happens ( even worse on Tahoes and "burbs )
2.5 hrs tops for the first time, and have co-operative helpers to move the bed