Remove the cylinder from a screen door lock

Locking Handle
for Screen Door

There are many videos showing how to remove the cylinder 
from a

European Profile Cylinder

Locking Handle for a Screen Door,  However, I found the the cam would not turn upwards on my European Profile Cylinder. There are suggestions to use a paperclip, blade or other thin implement.

self-retracting tape measure

But I did not have anything thin enough, so I cut a 100mm length off a small metal self-retracting tape measure and then cut that in half longitudinally. The result is a thin strip of metal 100mm x 5 mm, which has a curve matching the lock cylinder. I was able to slip between the cylinder and lock, then lever the cam up. Be careful as the metal strip was sharp where it was cut.

Having got the cylinder out, my next problem was that rather than being screwed to the door it was riveted. I used a Dremel type Rotary Tool with a miniature grinding disk to remove the heads of the rivets.