How does the coupling end of the fuel filter come apart? This one looks like it might be the original filter and it is very rusty.
Fuel flter replacement on 1997 Oldsmobile Achieva
If it is the type I am thinking of the fuel filter has a barb fitting that the fuel line pushes on to. To lock the hose in place a clip is in the bell fitting that pushes onto the filter. A tool is needed that pushes onto the barb and is then pushed up into the fitting to release the clip which is reusable. A company named Lisle make the tool it is about $15 and is available at any auto parts store.