The only one I have seen,, and which I think I can duplicate is shown in the Factory Shop Manual...617.95 Turbo Diesel engine page 01.8-417/5 F2 .... it pulls it out with a combination of threaded sleeves and nut which is turned with an open ended wrench, because above it is a hand tap holder type of arrangment...the base is at an angle and may have a couple of bosses on it..... Greg