Sorry, don't have any direct experience with the Astro Roof, so can't offer too much. I guess my approach in a case like this is, pull gently, and if that doesn't work, pull more forcefully. It's either going to come off or break, and if it breaks, it may have broken anyway. (Always looking for the...weakly and strongly retained areas, indicating where clips/fasteners are/aren't, and blindly trying to figure out how they might work) Even the standard trim, it was SUPPOSED to be removable, but it broke, so time to find new clips or figure something else out. And on the headliner material, I think a lot of it has to do with heat and oxidation, which is unavoidable. My headliner was also in shockingly good condition, until my ex-girlfriend discovered that when she pushed on it with her hand, it left a permanent hand print, which shortly turned into a sagging bubble. This eventually encompassed half of the headliner, so I was forced to pull it down and recover it. If your headliner also allows for permanent impressions, then it's probably a good idea to recover it, rather than having to do the job twice. Relatively easy job, and almost necessary if the headliner board is damaged on the removal and you need to repair it. I can offer plenty of guidance on this particular subject.