Carousel tray drive coupler broke

This coupler has a tab on it that keeps you from being able to push it straight down onto the motor from the inside of the microwave.
Turn off the breaker to the microwave or unplug it. Remove five screws that hold the bottom cover of the microwave. The cover will hinge down and hang on tabs at the back.
Unplug the wire connector on the drive motor by pulling it straight off. Remove one screw that locks the drive motor in place. Turn the motor slightly to unlatch it from its mounting tabs.
Place the new coupler into the opening inside the microwave. While holding/turning the coupling with one hand, insert the motor shaft into the coupling. It will only fit one way. Press the motor and coupling together until the motor can be latched into its mounting tabs. Secure motor with screw and install bottom cover.