help for disassemble

[cimerio]

Hello, I would like to disassemble my dead Fenix fd20. Can someone please guide me on this?
It seems like a "mono" unique piece, but doesn't make sense. Should be a way of dismantle it.

 

[yellow]

The bezel for sure is screw-on,
that "grip ring" directly below also seems to be threaded in.

As you surely have tried this already, did it not come apart?
Fenix in the past has glued in parts often.
Maybe heating them up could help.

 

[Monocrom]

A mini strap-wrench should help in getting the head twisted off.