cowie, no-one said he was going to paint the CAS. Just needs to remove it to get the cam cover off.
jwah,
The door is basically welded shut. However, there are openings on the inner panel to gain access to the components. There is probably a protective sheet of plastic on the door under the trim. If you carefully break the adhesive, and peel the plastic back, you should have access. But it's not easy access.
If you are only doing the rocker covers, then they can be removed without upsetting the CAS. If you do remove the CAS, take care not to break the half-moon locating key on the camshaft side.