The fuel pump has to come out through the plate on top of the tank. It's a matter of manipulating it to unhook the unit from the mount and then you have to work it out of the tank.
Replace the gasket and sealing screws when reassembling the unit.
I would suggest getting the factory HD manual.
The fuel gauge is in a rubber gasket and you wiggle it up and out, do not twist, then mark and disconnect the wiring on the back.
