I have a K100 radio box with a lock like this one in the Ebehhh offer.
Ebay
The lock is open and acts as a pushbutton. I want to be able to close the lock with my ignition key. I can find a Youtube video for every lock on the motorcycle, but not for this lock.
Does anyone know the way, a description, a video how to remove the cilinder from the housing?

If your box is exactly the same as the one on the Eeebaay link then there might be some difficulty as the one in the link is an R model key which looks to be a different format to the K model keys.

Good luck - I'm sure somebody with ex police rear boxes will have sorted it.

Cheers