are those studs replaceable?
why not take a dremel with a cutting blade, cut a vertical slit, try to split it open and wiggle it out.
vice grip and a hammer <---Ghetto mechanic
lock the vice on the sleeve and tape the handle together (duct tape) and hammer the vice. force should make the sleeve twist/spin
or just use the same sleeve mount all the bushings on the sub frame. clean the sleeve, grease it up, it should slide through.