The bushings have a steel core that the
bolt goes thru, and the edges are serrated
so they bite into the A-arm mount point, you
won't hurt them by pounding the bolt out, I
can't say the same thing for the bolt, be careful
to not damage the threads or it will be tough to
get the nut to start again.
Take the weight off by jacking up on the frame
until the wheel comes off the ground slightly, you
should be able to turn the bolt with a socket or
wrench, if not, get an impact on there and break it
loose, you might have some corrosion binding it
all together.
Good Luck,
Wild