Help with stuck Router Bit (Resolved)

Hi Everyone

I am new here - and to routing - I picked up and Elu Mof 177 type 3 on eBay - I am based in the UK.
Like an idiot I have managed to get a bit stuck in it - I did not realise that the nut and collet had to be popped together before inserting the bit. It is a straight spiral bit in 8mm and it’s in and 8mm collet.

I have tried WD40, I have tried gentle tapping, I have tried a bearing puller on the collet, I have tried widening the collet with 4 flat screwdrivers. I have tried backing the nut out against a mole grip tightened to the bit shank.

I am running out of ideas!

I have thought about putting the machine in a freezer? Or heating the bit.
Are either of these ideas sensible?

Does anyone know of a shop that could repair this?

I am based near Worthing.

thanks