I think he meant just the sun shade slider, not the whole sliding assembly. But yes, the headliner still as to be removed to get the shade out. There's another clip on the rear of the shade that has to be removed also (a real pain in the butt)!
It can be done w/out taking the whole headliner out. I did it on my 86GN. Took out the glass assembly to replace the gasket and reupholstered the sunshade. There's a nice writeup on it in the GNTTYPE Archives by Dan McCann. Here's a link to it
I have been doing a search for a while and finally found what I was looking for.
Although, the procedures for removing the Astroroof sound pretty intimidating, the directions read very well and to the point.
