How to Turn Grinded Enchantments Into Books
The book output
One of the main uses of the mod is converting an enchantment on an item into an enchanted book. That book can then be applied to a different item with an anvil, stored, traded, or saved for later. This is how you move a good enchantment off a bad item and onto a good one without losing it.
Extract the enchantment
Open the mod's interface and place the enchanted item inside. Select the enchantment you want to pull off. Choose the option that outputs a book rather than clearing the enchantment. The interface produces an enchanted book carrying that enchantment, and the source item loses it. Take the book out of the output slot before doing anything else.
Apply the book elsewhere
Carry the book to an anvil and combine it with the item you actually want enchanted, exactly as you would with any enchanted book. The enchantment transfers to the target item. This lets you consolidate enchantments from several junk items onto one keeper. Remember that combining books and items still follows normal anvil rules, so plan the order if you're stacking multiple enchantments onto one piece of gear.