Section 19 of the manual covers inspection and trouble shooting of the Control Unit (PGM), Servo Motor (RC Valve) and Oil Pump.

If you remove the pulley, that will give you more play to remove the control cables from the pulley. Loosen the adjuster nuts on the adjuster to get play in the cables and remove the pulley off the valve shaft.

As for removing the valves with the cylinders on the cases, it can be done, just do one at a time and drop the piston below the exhaust port.

Now I wouldn't recommend actually removing the valves that way as there is a lot of carbon build up on the valves/shaft that you probably dont want getting down into the cases and into the bearings.