wiring to my fuel pump is questionable upon inspection, so would feel much better rewiring it, better safe than sorry

need a bit of help, a guide, a wiring diagram, as i have no idea exactly what im doing lol. i believe i am in need of a 4 way relay? run fresh live from battery to pump, fresh earth, and use existing live from existing relay as a switch feed? basically im unclear, and any help would be great

cheers