Rear window stuck in up position-fixed

[2k35is]

Hi
Car is kept in garage with roof stored in boot.
Tried lowering windows and rear drivers side is stuck in up position. This has to lower for roof to work.
Tried pressing and holding all various window switches but no movement in rear glass window. Can hear a very soft type of click coming form beneath the widow.
Anyone got any ideas of how to investigate. Can the internal trim down from where the seat belt retracts be removed to see what's happening? If so any guides /help would be grateful for assistance.
Thanks

 

[2k35is]

Couldn't find any guides on removing trim etc so get at window regulator. Have already checked that glass not sticking to inner
or outer window seals. Just decided to spray some WD40 down between outer glass seal and glass. Second press of button and it started working Ok. Much relief not having to take it into dealers.

 

[Busterboo]

Glad you've fixed it.

Car is kept in garage with roof stored in boot.

Isn't doing this asking for trouble?