The fuel filter is located in line with the mail fuel pump, both underneath the fuel tank and covered by a metal cover plate. Simply lift the car a bit, remove the two 10mm nuts close to the rear bumper (one holds a bracket for a n overflow hose). Then remove the fuel filter while counter holding the 17 and 19mm nuts with open wrenches. Be aware that these sometimes are frozen badly and are hard to break loose. Use the best tools you have as the job becomes awkward once the tools slip.

Expect some fuel to drip out. Best is to make a small clamp to pinch the hose from the pump to the filter without (!) damaging it. There will still be some fuel spilling but not much.

The picture below shows  the degree of contamination you have over some years.

Refer to MyTip417 for more information of filters and part numbers.