Is there a way to operate the fuel pump (to drain tank) other than opening the air flap?

If you pull the yellow wire off the spade connector on the starter, the fuel pump should run when the key is turned to the start position.
You can also supply power to one of the 2 rear most pins on the 4 pin connector in the relay board. That will energize the fuel pump.

On my Djet the round relay for the pump, pop the cap off and hold the pump relay on with your finger. Mine runs like that with the ign off and not cranking it over.

well i hope you mean l jet. and there are two ways to do it easily, one you do not need a fuel pump relay on the relay board, because the fuel pump relay on a ljet is in the double relay. take the cover off of the double rleay and with the wires pointing down and the circiut board away from you if you press down teh relay tabs one of em will make the fuel pump run. or put a jumper in the relay socket on the relay board. also you could install a relay on the relay board in the fuel pump postion and put a wire in the rear (iirc) passenger side pin of the 4 prong connector, which l jet does not use, and ground it out. when ever it is grounded and the ign is on the fuel pump will run. just make sure you dissconect the coil so you dont blow it up. and when this is done you will need to change your fuel filter because it will have sucked up all of the crap in the tank. and dont let the fuel pump run dry it will burn up.

so simply put ignore all of the above and grap a hose and siphon it out, safer easier faster