The newer type ford  Transit

Has this type of fuel filter on it.You need to take out the air box on the bulkhead above the fuel filter(two size 8 bolts and a clip and lift out of the way.

Remove the outter metal cage protecting the fuel filter housing 3 size 8 bolts.Remove the two multi plugs and clips.Remove the fuel pipes two on each side of the fuel filter (press clips).

Take away the metal cage and your left with 2 size 13 nuts then remove and lift out filter housing.

There is a plastic nut on the underside of the housing/this is to remove the filter from the housing.Refit with new seals and clean out the bowl,fill back up with diesel,refit.