Hi Craig,
It's an absolute prick of a job, and nearly cost me my sanity, but if you want to attempt it I'll do my best to describe it to you.
It's quite a while since I did the job, so I hope my memory is fairly accurate
The best way to get the recirc door out is through the engine bay. If you open up the plenum cover on the passenger side where you get access to the cabin filter, the door is right behind the filter. I just used two large flat head screw drivers and put them on either side of the pivot points on the door and levered it out. And that is by far the easy part. Getting the new door in was an absolute bastard, and I don't recommend doing it the way it did it. This bit is very hard to explain and I can't take pics of it with pulling the bloody thing back out. The door has two spindles at the pivot point that slot into two holes on either side of the casing for the lack of a better word that the door sits in. Right next to those holes is a little plastic tab like a fin that stops the door from slipping out of those holes when the door is at the limit of its movement. So I managed to get the left side of the door in its hole but because of the tab, and not being able to see very much I just couldn't get the right side in. So I ended up cutting off the little tab and then it went straight in. If you have the same problem I suggest getting one of those little inspection mirrors and go through the inside of the car. Once you take the glove box and the blower motor out you should have enough room to see what you are doing with the aid of the mirror.
Okay, so I can't quite remember the exact reason, but I also had to take out the actuator that drives it. So I'm not sure if this was even necessary, as I know it was working as I could see it turning. Getting this out wasn't that hard. Putting it back in is a whole other story. So hopefully you don't have to do it, but if you do, looking at it from inside the car the actuator is on the left side of the door. So when you are taking out and putting back in the screws you are completely blind, lying with your chest on the door sill with your hand stuck right up pretty much as high as you can get it on the far left of the blower housing. I also had buy a tiny little socket set to be able to get the screws out.
Anyway that's as good as I can remember, and hope it helps. Let me know if you need some clarification on anything.
Cheers
Micky