There's a special tool for getting the case halves apart. The tool looks like a big C-clamp. The "C" part reaches inside the case and pushes (It pulls?) on the case towards the outside and the screw pushes against the end of the crank.
If you saw a picture of the tool, you could make one?
I have the Stihl 066, MS 660 workshop manual and illustrated parts if you need them but I will have to E-mail them to you?
Last edited by w8ye; 10-12-2015 at 05:12 PM.