Here is how to get a book with the “Mending” enchantment in Minecraft. This enchantment will automatically restore the strength of different tools, weapons and armor with experience.

Village Search

Find a suitable village. Try to choose a village with the fewest residents so that you don't disturb busy NPCs.

Find an unoccupied resident. A normal unemployed person has no special clothes like a robe, a farmer's hat, professional glasses, and so on. Also, he won't be working.

But such a resident can take up any occupation. Therefore, isolate him quickly. You can drive him into the house, or temporarily send him to a dug pit, from which he will not be able to jump out.

Build a profession reset mechanism

You will need the following items to get a book with “Mending”:

• Lectarn - gives the resident the profession of Librarian.
• Sticky Piston - needed to reset the profession.
• Button - activates the piston.

What you need to do:

   1. Bring the resident without profession to a convenient place and restrict his movement.

   2. Break the block in front of the resident.

   3. Place a sticky piston pointing upward.

   4. Place a lectern on top of the piston so the resident can "see" it.

   5. The resident will become a librarian and his appearance will change.

   6. Right-click on him and check if he offers a book with “Mending”.

If the book you want is not available, go to the next step.

Restart trade and retry

If the desired enchantment is not present, click on the button placed on the side of the sticky piston block to activate the mechanism and raise the lectern upwards. As a result, the working block will disappear from the resident's sight and he will lose the trade. After a second or two, the piston will lower the lectorn back down and the resident will see it again and take the profession of librarian anew.

Every time he takes a profession, he has new trade offers generated, so repeat the profession reset procedure.

Sometimes it may only take a couple minutes, sometimes a little longer. Most importantly, take your time and continue the cycle until the resident has a book with “Mending” in the first item on the item list.

If the book appears, quickly make a trade with the librarian and exchange the enchantment book for any other book you have. From this point on, the resident's offers will not change and he will always offer “Mending”.

After you buy at least one book, the inhabitant will no longer be able to change professions, even if you break the lectern. You can now safely place him in a more protected area, build him a trading hall or just periodically go to him for new books.

To use the Mending book, you will need an anvil. Align the desired item (such as a diamond pickaxe) with the book and the enchantment will be applied. The item will regenerate from the experience you gain from killing mobs, mining resources, etc.