Do not work on a vehicle that is supported only by a floor jack. Remove the right-rear wheel and set it aside.
Unscrew the gas cap. Locate the fuel pump, usually near the tank and behind the axle. Place a pair of locking pliers on the soft fuel lines that go into and out of the fuel pump.
You will have two pairs of pliers on the lines, one on each side of the pump. This will prevent fuel from spilling out when the lines are disconnected.
Loosen the hose clamp that holds the line to the pump, using a screwdriver. Pull the fuel line off the pump. Disconnect the lines that go to the fuel accumulator, if the Jetta is equipped with one. Disconnect the wires that go to the back of the fuel pump, noting where they for later reinstallation.