I presume the key is missing?
Remove the plastic surround on the barrel of the eurolock.
You can buy a specialist tool to break the lock, but it's pricey especially as you'll only ever use it once, hopefully.
Alternatively, grasp the barrel with a large Mole grip, and use a side to side, up and down motion until the barrel snaps. Remove both parts of the barrel, interior and exterior.
Use an allen key as a lever to rotate the lock mechanism and open the door.
Remove the fixing screw for the old lock, which is on the edge of the door just below the door latch, and install new barrel of correct length and profile.
It's not a bad idea to remove a working eurolock barrel beforehand to get an idea of what you are trying to do. The break will occur at the point where the fixing screw goes through the barrel.
bigsofty, November 2012
