Done it boyo's. Got a small drill piece and drilled the sort of middle of the bolt out (couldn't get it dead center because it was slipping everywhere so did a fully messy job), then got a bigger bit and made the hole bigger then used the smaller one to pick apart at the edges of the bolt, then a m5 sized drill bit to clean it all up. for some strange reason there was threads in there so I was able to screw a new bolt in by hand