Depends....
On my 2000 HR Endeavor I had an access panel in the side of one compartment that when removed allowed access to the area above the fuel tank. This area was part of the overall compartment structure and was made of the same material as my storage bins. In this compartment I found a 12 x 12 hole that had been cut right above the main fuel pump. Through this hole I was able to access the fuel line connection for the generator. Was a tight fit to get in and out but I was successful in replacing the complete line all the way back to the generator.
If you don't have anything like this you will need to drop the tank. That will require draining or removing it prior to refilling. Not a hard task with a couple of floor jacks and a couple of small pieces of plywood on top of the jacks, if the tank is near empty.
The new gas line solved my generator stopping issues I was having with my Onan 5500.
Hope this helps.
Michael
2000 Holiday Rambler Endeavor Gasser
2013 Honda CR-V Toad