Most people do something similar, here's how I do it. I take the fuel feed line that runs from the fuel tank to the carb intake and split it, then put a piece of brass tubing in it to hold the tube together when it's in use. To fuel the plane you split this tube and hook it up to your fuel pump, I will slip the fuel line from from the fuel pump right on to the piece of brass tubing. Then you remove the pressure line from the muffler and point it down and away from the plane. Pump the fuel into your tank until the fuel overflows out of the muffler pressure line. Then just hook everything back up.

Hope this helps

Ken