Use a small metal rod or screwdriver to push in on the other side of the handle while pushing in the orange LOCK OFF BUTTON with your thumb. While pushing both sides in, carefully rotate and pull the handle off with force.
Note: One side of the handle has a gear-like built inside of it to allow the handle to stay in position. In order for it to be removed, it will have to be in the correct position.
*Avoid removing the auxiliary handle unless you are replacing it.