Hi I have read all the posts on this subject but I am still having trouble. I have followed the instructions but when I press the release catch on the roof mechanism and try to pull the glass off, I can't move it.I don't know if this is something I am doing wrong or because,due to having a debilitating illness, I just don't have the strength. I wondered if I am supposed to lift the back of the roof higher.Any help would be truly appreciated.