You're thinking of a 69-70. They are not the same as a 67-8.
As others have stated the 67-8 roof pillar XR-7 emblems are held in place with two nutted studs per side. To get to the nuts first remove the rear seat, both sections. Then remove the interior rear side panels, this will require removing the window cranks, the little triangle corner trim pieces, and the edge windlace. Now remove the upper windlace, this is the trim piece that edges the headliner going above the quarter window and the door glass. You will need to remove the coat hook here too. Once the side panels are removed you will be able to see the bottom edge of the headliner material. Grab the material and pull it gently straight down, this will release it from the barbs that hold it in place. The headliner material wraps around the metal at the rear of the quarter window. You will need to loosen it from that edge. Be careful here not to tear the headliner if you are not planning on replacing it. With the material loose from the quarter window edge and the lower barbs you should be able to carefully lift it up. It will still be wrapped around the rear edge behind the rear window so do not pull too hard on it. You should be able to lift it enough to see the two access holes for the nuts. You will need to add an extension to your rachet to reach the nuts. You might want to add something sticky inside your socket or just be very careful as when the nuts come off they often will fall out of the socket and down into the wheelwell, where they can be a real PITA to get back out. Good luck with the project.
Randy Goodling
CCOA #95