Rear window brake light: drops down, fixing is loose

2001 Nissan Micra
The rear window brake light has slipped down. The fixing on one side has let go.
The fixing is a brass plate with holes, that locates with a rubber pad with nipples that is attached to the window.

It's very fiddly to get in place. I think you are supposed to turn the brass plate using a socket until it is place, then press.

Anyone done this successfully? Or is there a better method of fixing. Gaffa tape just drops off after a while.

 

Heat the inside of the car. Sandpaper the contact area and superglue

 

Then two days later, do it again.

 

Use the sticky pads used for rear view mirrors