An unmanned aerial vehicle (UAV) includes a body that supports one or more rotors, the one or more rotors each driven by a motor and configured to provide lift to the body. The UAV further includes a parts handler coupled to the body, the parts handler configured to grasp a payload, and rotate the payload with respect to an external structure to couple the payload to, or decouple the payload from, the external structure. The UAV includes a stabilizing mechanism extending from the body, the stabilizing mechanism configured to contact the external structure without transferring entire weight of the UAV to the external structure and prevent rotation of the body when the part-handler rotates the payload.