John,
Ignore my earlier post if it's still there. I decided to sacrifice one of my ST motor cores in the name of horological science. Here's how the bushing assembly is put together.
The entire carrier unit can be pressed out from the back plate. Grind down the rim with a Dremel and press it out.
Now you'll need to press out the little end cap on the back plate side of the bushing carrier. It's hardened steel and can't be drilled. (don't ask me how I know this!!)
Inside the unit are three brass bushings. One in the front and two in the back. I believe the back one is only partially drilled so it stops the rotor shaft end play. Ignore the bushing bores in my images. I mangled them up pretty good. Image #3 show how they're stacked up inside the carrier.
These brass bushings come out pretty easily if you catch the edge with a small punch. Remove the back two first and then the front one. Replace or rebush the bushings and you should be good to go.
Hope this helps. Let me know if you have any questions.