Been a while but I think there is a plastic nut on the bottom, unscrew and pull off the tube, inside is the float and the sender for the warning lite. There are 2 thin wires that go from top to bottom and they are fragile. That's for your warning lite.
the wires are stretched tite and soldered at the ends, if a wire is loose you can bend the tabs enough to resolder it then bend it back to stretch the wire, it will be obvious when you get it open.