How do I take the fuel pump off the tank

While holding the modular fuel sender assembly (3) down, remove the snap ring (1) from designated slots located on the retainer (2). See Fig. below

Remove the modular fuel sender assembly.
Install a NEW "O" ring on the modular fuel sender. Install the modular fuel sender to the fuel tank. Align the tab on front of the modular fuel sender with slot on front of the retainer snap ring. Slowly apply pressure to top of the spring loaded sender until the sender aligns flush with the retainer on tank.

NOTE:Be sure that the snap ring is fully seated within the tab slots.