Armytek tail cap dissasembly

I’ve had a switch failure and because Armytek shipped me a new tail cap I now have one to play with.
My problem is I can’t get the thing apart. It appears as if the ring around the switch boot must come off, but I can’t get the thing to budge.
I’ve had the cap in a bench vise and tried needle nose pliers in the provided notches but got nowhere.

Armytek provides a spare switch boot so they must expect the end user to be able to do this, I guess I’m going about this the wrong way.

Which armytek FL is it ?.
Some of them have a second cap which unscrews from the back to remove the clicky switch. Under that switch cover there is a ring which can be unscrewed with circlip pliers and the whole thing will come out when that’s removed.

Good point, thank you.

It's the Viking 2.5

The spot I would normally tighten my 4sevens lights doesnt have any dimples and I think it may be all one piece with the side wall.

The ring around the switch boot has a bunch of scallops that my needle noise pliers fit into perfectly but the cap twists in my vice before the ring lets go.

Ahh yes, i do remember that,
Here
Is a review by JohnnyMac and he says in his cons part that it is tight. He also says it is further down in the review.
I suppose that it is locked in with alot of lock tight.