Hair bonding refers to a method of applying hair extensions using an adhesive to "bond" the hair piece to your natural hair. Usually it’s a rubber-based glue, which you can purchase yourself from a beauty supply store or pharmacy. The hair weft (available for purchase from a beauty supply store, online, or at a salon) should be applied under a layer of hair. If you’re going to (bravely) DIY this, we recommend a lot of mirrors and maybe a friend to help you. Apply the glue to the weft and apply it right below the part, being careful not to get the glue on the scalp. Once you want to remove the weft, apply a hair bond removal agent, which you can get from a beauty supply store. Carefully part the weft from your natural hair. You may need to apply the removing agent several more times to get all of the bonding glue out of your hair.