Need help with euro cylinder

[squonk100]

Hi, I am trying to replace a euro cylinder lock on a pvc door that is around 20 years old. It has a multi locking system. I know where the securing screw for the lock is supposed to be, but mine is not there lol. I have taken off all the screws from the multi lock strip but there is no securing key for the cylinder. I have not removed the strip completely as it is still fixed to the door by the multi lock mechanism.

Would the securing screw for the lock be under that? Thanks for any help

 

[crank39]

If the hole is there but the screw appears to be missing then it's probably a long grub screw so you'll need a tiny Allen key that fits down the centre, probably something like a 3mm

 

[squonk100]

Thanks crank39. There is a deep hole there and I have just had a look with a torch and there is indeed a small grub screw in there!

Never even thought of that *facepalm* lol

Thanks very much for your help!