Disassemble A Wohlhaupter Upa3 Boring Head?

I just need to remove the top part that the shank is integral with. It is an iso 30 or 40 taper and I need to machine it to be a straight shank. But to do that I have to get it apart without wrecking anything. Stefan Gottswinter has a video on machining a shank on one of these with carbide tooling and it is doable. The material is hard but not too hard. Just have to get it apart. Any advice welcomed.

Scott in Montreal