You should insert the new level sender assembly into the slot, slide down until the lock tab engages, route wires next to the regulator ground wire and up to the electrical connector, slide the level sender wires into the open slots in the electrical connector, connect the electrical connector into the flange, test the level sender resistance with an ohmmeter, install the module into the tank, measure the resistance across the level sender with tank upright, roll the tank over and then return the tank to the upright position.