You may just need to replace the seal that seals the unit to the tank. But check carefully that the fuel line connectors aren't leaking.

Don't remove the unit unless you have less than 3/4 tank, less is better!

Depress the white part of the fuel line clip to get them off. Be very very careful, they can break fairly easy, then you have to replace the complete line!

There are o-rings in the clips that seal the line to the pump, be careful not to disturb those when installing the line.

There is a special tool to remove the ring that holds the unit in. You can probably get it off with a little ingenuity.

Good Luck