Locksmith drilled door to unlock it, how would I tighten the cylinder / remove the cylinder plate

Hi friends.I paid a locksmith to unlock my door, he used a drilling method as he couldn’t open it any other way. Ever since the cylinder has been loose and does not open unless you push on it when turning the key (otherwise the key gets stuck).I am leaving my tenancy soon and want to fix it before then, happy to pay but don’t know who to ask. I am unsure how he removed the cylinder while the door was locked, as there are no screws – could anyone assist in how to repeat his process. Is there a way I can fix it?Thanks so much for any assistance.Photos here: https://ift.tt/j39EiHY via /r/DIY https://ift.tt/ecix4BM