1. Acquire a large number of stat boosting items and gold.
2. Save the game.
3. Recruit the character from the logbook you wish to boost stats for.
4. Apply as many stat boosters as you can to this unit.
5. Update the avatar logbook for that character.
6. Save in a new save spot (do not overwrite original save.)
7. Load older save.
8. Repeat process until stats are maxed.