Seatbelt Webbing "Stoppers"

[RBZ5416]

Couldn't think how else to describe those little plastic discs in the webbing that stop seatbelt tongues sliding down too far.

Anyway, on my elderly 320i the tongue for the rear centre has somehow got past the stopper. I can't imagine how & no amount of "persuasion" will get it back. Do those stoppers just pop apart (& more importantly, back together)?

Luckily during it's MOT today the tester didn't notice that now no one with hips wider than about 8" could use it! Ninth straight pass by the way!

Edit
Funny how posting can focus the mind. Replacement Seat Belt Stops available from Ebay & it looks like they have a pin that has to be melted into place.

 

[RBZ5416]

Well just in case it helps anyone else:

Knowing replacements were readily available, I stuck a flat-bladed screwdriver under the button & twisted. It popped straight off. Moved the tongue & it popped back together again.

Still can't fathom how it happened though.