Smack it!!
Yes try and use some lubrication, from what you describe the bolt is usually rusted to the bushings. Trying to get oil into the rusted area is really difficult. That doesn't mean you shouldn't try. Use plenty of your favorite penetrating oil over several days trying to get the oil into the rusted areas. Now, if you don't have a 1/2 to 3/4 inch in diameter brass drift about a foot long and can't borrow one, go to you local hardware or building supply center or where ever you can buy brass rod material in about 3 foot lengths. Buy whichever diameter rod that is as close to the outside diameter of your bolt as you can. When you think you're ready, use about a 1 foot long section and a 3 pound hammer. You're going to drive the bolt out. Brass is a softer metal than the bolt so it won't damage it. Hold the brass rod section with a LARGE pair of Vice Grips, so you don't hit your hand. I'm assuming you don't normally perform this type of work and I'd rather you beat up the Vice Grip with the hammer blow, when you miss the striking the brass rod than your hand. Now put one end of the rod on the end of the bolt (you've got the nut off of it right?) and smack the other end of the brass rod with the hammer, "Hard"!! Again, Again and Again. If after repeated blows the bolt isn't moving you can choose to soak it more with the penetrating oil and try hitting it some more or it's time to use an air driven impact punch. This will damage your bolt, but it should drive it out. :bang: :bang: :bang: :bang: :bang: