You don't need any special tools.
1. take the spindle cardridge from headstock.
2. mark "0" point of bearing. remove old bearings.
3. remove the spacer.
4. put on new bearing untill proper tension
5. measure new lenght of spacer. check if original spacer fits.
6. take away bearing
7. put on the prepared spacer
8. put on new bearing and nuts and all.
This will ensure proper tension of bearing. It's not a manual nor training material. Just brief description.