Pull out spring-loaded accessory release button (you load bits by pushing them into the chuck; to get them out you must push this button).
After peeling off the adhesive stickers that span the joint pull the housing apart and remove the mechanical parts.
Pull controller off the bearing on the back of the rotor (the rotor is the part of the motor that spins).
Here are the main components of the brushless motor. Brushless motors are more durable (no brushes or commutator to wear out) and more efficient (so they boost the runtime of cordless tools) than conventional brushed motors.