I want to paint them black, along with the mirrors.

Maybe you could call down there and ask him how he got them removed? His car was slammin though- he worked for the Porsche dealer, probably got a nice discount on paint / bodywork. But it sounds like you want to put the rails back on after painting?

to undo the bolts BUT you need to be very careful not to bend the headliner. Probably safest just to pull the headliner completely out. Not bad, but then again not real fun either. One advantage is having the rear hatch.