1. Don't know.
2. Take a look here. May not be what you'll do but has some information you can use.
http://www.mazdatrix.com/faq/rrsteer.htm
I recommend removing the entire knuckle assembly so its easier to press in/out with a vise/press/threaded rod. You can also replace any other old (20yr old) suspension rubbers and clean the suspension while you're at it.
3. Dropping the subframe may make your life easier if you want to do this. It's heavy if you have the diff and arms still attached so be careful.
4. Safety first. Consult the FSM too.