Fuel Pump Replacement '90 MM-2.4

I'm trying to drop the fuel tank to replace the pump on a friend's Mighty Max. I'm having trouble getting off the main fuel line going into the tank so that I can drop the tank to get to the fuel pump. Anyone have any suggestions? It doesn't seem to want to come off easily, and I don't want to damage the fuel line by twisting it too much. Thanks very much for any help!

Does anyone know where the relay/fuse might be for this truck? I installed the fuel pump and am still not getting any humming noise out of the pump. Can't find the fuse in the regular fuse box. Thanks.