Yet another window issue! - Stuck rear window when going up.

Hi.

Seems like window issues come in threes!

This time the rear nearside electric window jams when rising. This seems to be because it is tipping towards the central (B?) pillar. I've taken off the trim and covering by the C pillar but can't see anything obviously wrong on this side. Access to the inside by the B pillar seems to be by taking off a plate onto which the motor is attached. I haven't done it yet as am not sure how fiddly it is. Was also thinking about greasing the rubber channels first because maybe it is getting stuck there on this side. Any tips or suggestions?

Cheers

Tom