If you have a look right at the bottom of the handle, you should be able to identify a small pin that is pressed in. Tap this pin out, and the barrel should all come out. Wd40 if its tight and use your key to turn and free it up. The Barrel can be disassembled and refitted to suit your door lock keys if they are different. Will try to find my spare handle for a photo if you get stuck. Cheers..