with the nut off if the front one is being a *****. lift the cab up on that side. heat down into the sleeve with a torch. get it HOT!!! hold with LARGE channel locks. and lower the cab down quick and have someone else sit on the core support and then impact out the bolt. this has to be done quickly.... lol... if that doesnt work cut the head of the bolt off jack up the cab pull out the sleeve with the bolt inside it put it in a vice and put visegrips on the bolt sticking out and HEAT THE **** OUT OF IT and then unscrew it in the vice...
with the head cut off and it in the vise out of the rubber you can heat directly on the sleeve where its threaded..