207 crank pulley change

[zooankski]

Right guys, need some advice.
I have just been quoted £145 for Peugeot to change my pulley. I have the parts already (new pulley,belt and replacement bolt which are all original parts)
So that would be a grand total of over £200!
I belive i need to lock the flywheel with a 12mm rod through a hole in the case somewhere to aid getting the bolt out?
These bolts are threadlocked in place so i guess my best option would be to warm the car up first just to make it a little easier????, i am having nightmares about the bolt shearing off!
Once the bolt is out, is there any possibility of upsetting my timing???? i think there was a problem with the set up once on certain models as there was no key in the crank shaft and timing could slip??? Backup shows mine with a key and i assume this keeps the timing pinion and the pulley fixed????
You can see the key in the pic (item 70).
This must be a similar set up on most pugs so any hints and tips would be very appreciated.