Roof Rack and headliner

[cDove]

'91 Rodeo, 196,000 miles, Original Clutch!
The Yakima racks have taken their toll and loosened the factory rails which now leak water through the mounting screw holes.

The factory mounting screws are loose but cannot be unscrewed; they just turn 'round and 'round. Looks like I have access them from below, underneath the headliner.

Is there a better way? What are all the attachement points for the headliner that need removing? Is there an easier way of removing the headliner? Any tips/pointers/gotchas?

-- Chris