I did it today. Took me 2 hours, easy pz.
After replacing the throttle actuators, clean and lubricate the linkages.
Also after opening my old throttle actuator, I realized that BMW didn't put enough grease to begin with, hence why the gears were grinding each other.
I might take my two actuators out and apply a high temp grease (very hot, where the actuators sit) to prevent wear on the gears again.