When you replace the swingarm bearings , remove the dust shield of one side of the bearing and fill it completely w/wheel bearing grease . Put the dust shield back on and install this side in away from the outside of the bike. .Roller bearings come w/just enough grease to not rust. This bearing is not going to roll but pivot a few degrees throughout it's lifetime so grease is going to make it last from now on.
When you are ready to install the pivot pins grind a bevel or taper on them so they will go through and into the bore of the bearing easily. If you crossthread these pins , just remove the swingarm and screws them from the inside out to clean up the threads .
Good luck & keep us posted !