Bongo Fury

I sent my aft up today but when I sent it down only one side was moving. upon further inspection the worm drive (chain) on the passenger side has come adrift from the mechanism but I cant see where to anchor it, looks like the roof may have to come off to re-attach it. the side that has come off runs up the inside near the tent which must be the side to bring it down as it goes up fine!
has anybody had this problem before or know how to help.

problem solved (thanks to Ian Taylor, jap car imports) had a new chain fitted to slider mechanism.

AFT probs can be a real pain, I know as I've had them, please to hear you got a good fix.