What is the best way to remove hair extensions?

It all depends on how were the extensions put in (sewn, bonded, braided, fusion, etc?)

Braids, Cornrows, Twists, Locks - Integrates extensions in a visible way in that the braided attachment is seen but blends into the hairstyle. - Unbraid CAREFULLY so you won't knot your own hair

Bonding - The extensions used for this method have a latex plug meant to be glued to your own hair for short terms use. Because this method is fast it's also inexpensive. However, to remove extensions, oil and/OR heat must be used to dissolve the bonding agent, which messy and time consuming. If not removed with care the latex can pull your own hair out.

Metal Clamps or tubes -Can break off real hair, can be difficult to pry open later, and adds additional weight to hair.

Adhesive-Based Fusion - Wax-based. The adhesive remover that is used to remove these dries the bonding agent to a powdery substance instead of heat or oil

What is the best way to remove hair extensions?

You need a professional in order to remove hair extentions, because i think it is a special kind of bond on your head.