Liberating an xd freehub from a cassette

If you have a vice then you get two bolts and set them in the vice so that you can put the cassette face up with the bolts positioned such that the ‘arms’ of the cassette will resist you turning the cassette. Then use your normal cassette tool with as much force as you like… I’ve managed to get really stuck cassettes off this way.

That's the problem, if you look at the centre, the splines are utterly mashed. The last person (ahem, whistles, looks around, kicks stones) to try and do this has managed to put enough force in to skew them all by a significant amount, and it still didn't budge. I think destructive extraction is the only remaining option.

Oh right. I didn’t look at that. Impressive!

Very careful dremel work might be the way forward then. Cut a slot to relieve stress?

I know it's obvious,  but is a new freehub completely out of the question? 

I've only ever used HG freehubs so I was having trouble interpreting that picture within my reference frame of cassette lock rings etc.

A bit of research suggests that XD cassettes actually have the thread at the inboard end - and those diagonally slanted features in the OP's pic should be straight, like here. So, if I'm right, rather than unscrewing the inboard threads and releasing upon application of a tool at the outboard end, the whole cassette (or just the narrower bit at the end?) has twisted counterclockwise?

Impressive!

I'm not even sure a Dremel will save that unless you can cut off the whole thing very carefully!

There's 3 parts, the outer bit is the cassette, then there's the (for want of a better term) the carrier that sits on the splines at the end and supports the cassette, then there's the lockring sitting inside that. I think you'd have to cut all 3 off to get at the stuck threads?

And even then....... I've got a Gussett SS kit that threads onto those threads, and it will never come off again, I've had it in a vice with a breaker bar, until the workbench moved!