If the grease thing don't work, there is a tool that will. It is basicly a slide hammer with a hook on the end (well it is not a hook) but it grabs the bushing on the bottom side and allows you to drive it out. And use a wooden dowel with a frozen bushing (put it in the freezer for an hour os so) then drive it back in You don't want it to get marred up when you install the new one.
Note: You can buy a can of stuff from your local welding supply and from some parts houses that when sprayed on a surface will freeze that surface. Great for removal of broken bolts and stuck bushings.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"