Default [Q] My nexus 4 cam lense popped out.

This morning i found a small plastic square with rounded corners on the floor. Could not for the life of me fugure out what it was. So i put it bit and pieces box. Next thing u know. I was using my phone when i felt an unusual indentation on the back of the phone when answering it.
"Ding". So now how do i get it back on. On close observation it looks like some of the tiny adhesive strip is still on the lense whilst some on the inside of the rim. Tried to re-sit it back but it just falls back out. Dont think i will try glue. I may botch it blurring the lense with my fat uncordinated fingers. So pls any suggestions?