Wishbone ball joint removal

Does anyone have any idea how this is done cause I havent a clue and even the garage I took it too can't manage to get the ball joint out of the wishbone

 

Any idea how much or where to get one of these
Might end up being worth doing the whole arm

 

That's what I thought, but the garage won't use heat incase they either warp the wishbone or the ball joint explodes and I don't have the tools to use heat

 

As you can see my attempts are not going well

 

All the grooves are knackered

 

Yeah I really went for it
I have had to get a new wishbone,
I wonder if cutting the old ball joint in half and then welding a metal bar to it would work