Final update on removing these bastard exhaust studs.
They are out.
Credit for beating them goes to A Wise motorcycle workshop
Now I've got the job of cleaning the head up and prepping it for coating to make it new again.

If you are on the UK south east coastal region and you need a bike mechanic or workshop, I cant recommend these guys enough.

A wise motorcycles 
unit 5, Enterprise Units,
Durban Rd,
Bognor Regis
PO22 9RU

Its a tucked away little old school workshop that you can drive past without ever knowing its here.
Highly rated absolute gem of a little place.