Pull off sides of bearing using tweezers. Be careful to not pull on the metal parts inside of the bearing
Degrease the bearing using isopropyl alcohol. Soak for at least 20 minutes.
Dry bearing using heatbed of printer at 80deg for 20 minutes
Add Silicone Lube to inside of bearing
Add Heat Insert
Add the heat insert to the outside of the Left side.
Assemble
Push-fit bearing onto gear.
Holding the inside of the bearing between your thumb and forefinger, spin it. Adjust the fit until there's no wobble. Once you find that spot, glue it in place with light CA glue and spritz it with the accelerator.
Add a drop of light CA glue to the threads of the heatset insert, give it a spritz with the accelerator and then quickly Screw the Right side into the Left side through the bearing and tighten.