High Volks

How do I get the diff vacum servo out? I have undone the two screws, 
but then I cannot get them out. They are too long and get stuck on
 the drive shaft. Do I have to take that out too? How do I test the 
diff lock? What is the best way to get all the wheels off the ground 
so I can test the diff? I hope to get to know my SYNCRO a bit better 
so I dont have to ask too many questions, but first I have to find
 a manual here in the "lucky country".

Thanks

Tom 
89 syncro "permanently high" (roof)