Since I followed this mod somewhat early on, I knew what to do, but I'll admit that I've been wondering about the documentation side as well. I just figured it was fairly low priority seeing as this is a wip.
Anyways, jeremysb, it seems you can see what level you are and how much experience you have by pressing enter to open the dialogue box, then typing /expbar
Then, just go to a workbench and you should be able to craft the Novice Token for free. You'll have to equip the Token in order to gain experience from killing enemies. Once you have enough experience, the option to craft Tier 2 Tokens will be available. Crafting Tier 2 tokens will require you unequip the Novice Token and it will reduce your exp/level, but it'll be worth it.
Once you get enough experience after that, you'll be able to craft Tier 3 Tokens. If you level up the Tier 3 Token, it'll pretty much be the most powerful accessory in the entire game. Even moreso than the OP accessories from other mods. The trade off is that it'll take a lot of playing and grinding. So you'll have to earn that OPness.