'Once one learned what the engine needs, it was easy. Prime by pulling the ring that allows fuel into the inlet manifold, pump the fuel pump lever up and down listening for the 'clack clack' of the non return valves in the fuel lines (the tanks are downhill of the engine in the tail-down attitude). When fuel trickles from the manifold drain onto the apron, stop pumping and wait for the dribble to stop.'
The trickle is important - if no trickle the drain pipe could be blocked (old oil) and the manifold full of fuel.
Been there, done that.