aeomaster32 pretty much summed it up. Your Pegasus .40 will come with the fuel lines installed. You simply disconnect the carburator line and plug the filling nipple into it that comes with your fueling cap kit. You also unplug the vent line from the muffler and point it to the ground away from you. Flip the power button on your fuel pump and fuel will flow into the tank through the carburator line. When excess fuel starts coming out of the vent line, your tank is full.

That's why I said electric pumps can waste a lot of fuel. With a hand cranked pump you can stop fueling almost immediately, but if you're not really quick with the off switch on your electric pump, you can make quite a puddle under your plane.