Each of the 12 characters has their own Trait Tracker. You can identify them by looking at each character’s stat tracks, as they’re all unique.
For each color of character, one tracker will have a flat backside, while the other will have three raised sides. Apply glue to the three raised sides, then line up the two trackers back-to-back and hold them together while the glue dries. Wood glue is strongest, but white glue will be fine.
Once the glue is completely dry, open the top a little and slide your character card down inside. Apply firm, even pressure until it’s securely settled against the bottom walls. You can tell when it’s gone far enough when the little tab at the top of the tracker can be closed completely.
If you’re going to keep your characters in these permanently, apply a dab of glue to that little tab and seal it closed. If you want your characters to be removable, leave the tab unglued.