Remove two T5 torx screws near the trigger to separate the cover for the buttons.
Hold the cover down while turning the controller upside down to avoid spilling the buttons.
Unscrew four T5 torx screws around the controller to separate the bottom PCB. One is facing outwards near the trigger. Three others are opposite from the battery compartment.
Lift the wires up, and then remove the handle. Make sure to disconnect the wire or you may sever it.
The PCB also serves as the surface for the spring backing the trigger. Re-inserting the PCB with the handle still attached (for instance when cleaning) will require a separate tool to push the spring back while positioning the PCB back into place.