Originally Posted by PaulR  Robbo is correct. You need a key to turn the lock barrel slightly and then you undo the small grub screw holding the barrel into the door. The barrel will then slide out as the tumblers are flush with the barrel. |
As the door can be opened, I have already found and taken out the small grub screw to see if the barrel would slide out, which is when I found the retaining design of the lock.
Damn, I hate drilling locks, metal filings everywhere for cats paws to pick up.