On the biggest units I've seen techs in the field cut bushings out with a torch if nothing else works. I'd be terribly reluctant to try this on the relatively small bushings on your hoe.
Seems like there was a thread on here sometime back about using a hacksaw blade (recip saw? too fast? lack of control?) and carefully slowly cutting a groove in the bushing. Once the bushing could relax, the poster reported it came out without too much trouble. Die grinder using a burr might also be a consideration.
In the shop they'll commonly heat the outer side with a rose-bud and use sledge hammers to beat the bushing out. Even though not like welding I'm also hesitant to do much heating. And then repaint.
I don't know how you'd go about cooling the bushing enough to make much difference.
The best deal I've ever seen used is a portable hydraulic press that allowed the bushing to be '''eased''' out instead of just beating the heck out of it. Even then it was all the Porta-Power could do (unsure if HF knockoff would have the power / strength). Might find such a critter available locally for rent or borrow.
Be aware that in some machines the bushings are tapered so be sure you know which way to apply force. For your hoe I simply don't know.
Mine too are a little bit sloppy. After examining the repair possibilities I tighten mine up with grease daily and plan to continue using in this way until I note the wear is starting to get out of the theoretically replaceable bushing into the boss. I figure I'm good for another few hundred hours of backhoe use.
WRT greasing, make life easier by investing in either a battery or pneumatic grease gun. Also handy is a Lincoln or Alemite 360-degree swivel snout on the hose-end. Next time grease is on sale for $0.99 tube stock up.
Like Don, I'm curious how you proceed and your results. Would greatly appreciate your continuing to post if you do the work so we may all learn. If you do, photos would be great.