To turn your Diamond armor into Netherite armor, you need to get your hands on a Smithing Table. You can craft one by placing two iron ingots over a 2x2 square of wooden planks or they can also spawn in villages. When you've got one, just grab a Netherite Ingot and combine the two.

How do you make Netherite items?

To turn your Diamond equipment into Netherite, you need to have one single Netherite Ingot. Use the Smithing Table, put your Diamond tool on the left-most square, and the ingot on the next. This will create a Netherite tool, which is stronger, faster, and more durable than anything Diamond.

Is Netherite armor repairable?

Netherite ingots are the repair items for the netherite tier and armor material, and thus can be used to repair the following items in an anvil: Netherite Helmet. Netherite Chestplate.