More than likely would need a locksmith although a lot of joiners may know how/where to drill the cylinder and their rates tend to be a bit cheaper than locksmiths. If you could take off the handles or keyhole cover (escutcheon) leaving a bit of the cylinder sticking out, it may be possible to snap the cylinder in half using a heavy pair of mole grips. If this worked it's a bit tricky to try and fish the bolt back if you don't know what you are looking for. You have to lift a little spring and at the same time drag the bolt of the lock back inside the lockcase. If you are not sure, don't do it as you may end up needing a whole new locking machanism as opposed to just a new cylinder.
rdpaterson@dundee.ac.uk, October 2008
