'92 318is sunroof

I purchased this car a few months ago and the sunroof was not working, as such. It makes a clicking noise as if a gear is slipping and tries to lower itself crookedly. I don't need it during the winter but would like it working for the summer! The inner liner is half closed. In the Bentley manual it says to lower the roof a little then push back inner to acess cables etc. I suppose I need to close the inner, then lower the roof a little to then be able to slide back inner?? How do I get the inner to move when I can't really move the roof? I suspect that the cables are loose as well because it makes a rattlying noise on rough roads ( most of the time here in Quebec!). Would I damage the inner by forcing it closed or open?
Many thanks, Api