Craft 1 book
Craft 2 diamonds
Craft 4 obsidian
Open a crafting table
Place 1 book in the top middle slot
Place 1 diamond in the middle left slot
Place 1 diamond in the middle right slot
Place 3 obsidian in the entire bottom row
Place 1 obsidian in the middle slot of the grid
Take the enchanting table from the result slot