New PVCu Door looked in frame - no lock!

[iamwill]

Hi, new to the forums and having a problem that is driving me mad! Bought a 2nd hand (brand new) conservatory. The PVCu door is in the frame but is locked, however the Euro cylinder is missing so we cannot open the door! I cannot get the right measurements for the size of the replacement cylinder and nothing is mentioned in the documentation. Can the door be opened without the Euro Cylinder so i can get the right measurements etc?

Really grateful if someone can help...