Thanks Brian, read the thread looks like a pita
Yeah, it is a bit. The first time I did mine, it took about 4 hours ....... I likes to sit and think. The second time I'd got it down to about two hours.
One of the most fiddly bits is getting the window to go up and down to just the right place to get the frame out of the door. In the write-up, the bloke just pulls everything apart and does the job, I found that once I'd got into the door, I reconnected the window switch so that I could control the window up and down from where I was.
You'll need Torx drivers for your socket set, two sizes, sorry I can't remember what sizes off the top of me 'ead. The actual job is relatively straightforward, no adjustments or other catch-outs, it's just a bit of a fiddle. If you do have to go down the route of changing the lock, don't let the little linkage just dangle, remove it completely and put it in your pocket. If you let it fall in the door, trust me you'll be very lucky indeed to even find it again.
Sadly, you'll probably have to get the frame out to see what's going on with the little linkage. If the linkage is present then I would say that a replacement lock might be required. They are easily available, both new for about 70-80 quid and "pre-loved", AKA second user for about half that.
The part number for a replacement lock unit is FQM100700 for the right hand one.