The hoses in red are coming off the fuel pump, I don't know which is supply and which is return, but that won't matter if you install the electric pump. I also believe that hose in the blue is a return line, considering it's location. If your installing the electric fuel pump you can plug that hose up. Before you do that, make sure it isn't the fuel supply line. Just follow those two little hoses you circled in red and they will lead you to the fuel pump. Check for a big hose going into the pump. It should be bigger than the hose you circled in blue. You can detach the big hose and connect it to the fuel inlet you circled in red. And take off the mechanical fuel pump and put a block off plate if you can make one. Or just Leave the pump on in the meantime.