Don't remove the inner sleeve from the pin until you have chosen and acquired the new bushings. Some aftermarket hard poly bushing require you retain reuse that sleeve inside their bushing.
There is a Youtube video about correcting the spacing/gap between arm halves, correcting torsion pivot movement. He does weld on the aftermarkets reinforcement plates but a few little pieces of flat bar welded across accomplishes the same tie together.
And another member linked a video before I could finish my post. LOL Good luck with it.