Thanks.
How long did it take to fit? Sounds like I need to do mine too
Well it took 30minutes for me to get to the point where I could remove the thermostat housing. Unfortunately I didn't drain the coolant from the reservoir. I know. Fail. So I had to clear up that which took a while.
The thermostat seal was very perished and came off in bits and it took some persuasion to come out. New one just pushed straight in. Make sure you buy two new O rings that give the seal to the two metal pipes which lead into the block.
Then getting that plenum seated into the throttle bodies again was a pain in the arse. But like with everything, there is a knack to doing it. Put all your weight on the plenum and rock/shake it side to side to get it to fall into place. Then the biggest pain in the arse out of them all - that ******* PCV hose on the rear right of the plenum. Trying to get that hose to clip back in is bloody impossible. There's just no room to get your hand to squeeze with enough force to push it into the hole on the plenum. This one hose I struggled with for 1.5 hours and finally got it. I think the trick was instead of trying to push it into the hole squarely, to put it in at a slight angle so that one side of the clip clicks into place, then lever the other side of the clip into place. This will mean more to you if you end up DIYing it.
In the end the whole job took about 3.5hours. I think i could easily do it again now in under an hour.
A Mahle thermostat cost £21 and I also bought a new FAE temperature sensor for like £12 which screws into the thermostat housing since I had it all in bits anyway. New O rings will be about £3. Reuse the old coolant you removed from the reservoir.