This addon adds the ability to enchant over levelled enchanting books such as Sharpness X, Protection X, etc. in a survival world. These books can be obtained through tomes which are craftable.
To craft the tomes, you need to craft an Overenchantment Table which shows up in the recipe book. You can use this new block to craft all 5 types of tomes. The higher tier the tome the better the enchantment book you will get. To get the experience vials you have to craft an empty one and then right click with 5 levels. If you need any additional help you can craft the Custom Enchants Tutorial Book using 1 book and 1 lapis.