Rear window been tampered with...

[jonnyivy]

Hi folks,
              Yesterday my young son says his window aint going down,... so I tried it and just made a clunking noise !
On closer inspection someone previous to me has slipped a small piece of cardboard between the side guide and the glass which tells me there has been issues before.
I tried squirting silicon lub down the channels but obviously too late for that.
Is it a DIY  job to remove the door card and have a better look ?
Thankfully the weather just now doesn't need the window down !

Jonny.

[X5Sport]

Yes it is a DIY job.  Plenty on here have done it to sort out the vapour barrier, door handles etc behind it.  The barrier has to be put back correctly or you will get wet carpets!