Firstly, can anyone advise please whether these are good quality and secure ? I don't mind spending a bit of money to buy more secure ones if available. If I decide to change them how do I remove them from the UPVC door ? I have removed the fixing bolt but the cylinder is still held in place by the cam, which seems to be fixed. I don't really want to mess about until I know how to do it properly.
Thanks in advance
Steve