Subframe now scrap

I’ve spent 2 days stripping down the sub frame to find out what the problem was, I have found two problems, the first is the top arm bushes were worn down, all they would need is replacing and refitting. However the second issue is a bit harder to sort out, the lower drivers side arm cannot be removed? I have a 36″ breaker bar and with that on and me stood on the end of the bar bouncing up and down the bolt hold solid! the lower arm bush is also worn away.

Unless I can angle grind the bolt away without damaging the sub frame I fear its scrap. Not the end of the world, as I know of a 2300cc sub frame I might get and use as the base to reassemble.