see I was wondering the same thing bc there is a little cover with plugs on the top of it right over were the gas tank is in my hatch area. But I thing that may just be the sending unit.

 

What year car is that?In 92-95 civics you dont have to drop the tank it unbolts from the top,take the seat off and see.Its not hard to take it out.Make sure to have rags ready to soak up some of the driping gas.oh my bad edit: its a old rex,info might help sorry