I know when I changed my panhard rod bushes, I managed to get a big bar behind the bolt head and a big hammer behind it and after about an hour she gave in :')
I have lts of metal bits in my shed...you never know!
Job done. New bolts were plenty long enough so welded 4mm thick plates over the oval holes and jobs a good 'un. No more clunking and nice new bushes fitted so should be good for another 10 years or more.