E30 Zone

Hoping somebody can advise me here, the ZF manual doesn't go to this level of detail.

I'm guessing I need to press out the small pin at the splined end, but am i missing something else? The 3 slots on the spool valve look as if there is a retaining ring that can be picked out.

Cheers.

Bump cos I still havent got my spool valve disassembled.
I'd really like to find a bit more info so I don't make any avoidable mistakes.
I know depowered E46 racks are not uncommon on E30s.
I've found plenty about looping the lines (friction must be awful), and some info on just removing the main seal. But what are people doing to eliminate the slop in the rotary valve??
The skinny torsion bar allows a few degrees of movement between the steering wheel and pinion which must ruin the steering feel of the car.
I found this image of a ZHP rack from the Rackdoctor but they naturally don't explain how to disassemble or weld the assembly.