1997 VW Passat tdi 90 - Passat fuel filter - Tedster

tried to change the fuel filter on my 1997 vw passat tdi 90. Removed the pipes from the top and the two small screws from another. The new filter which doesnt come with the connections and it appears as though the top of the old filter seperates and is screwed into the new filter.However there is no screw/bolt allowing for its removal? Help please??