Steps:
Disconnect the hose tip from the mixer funnel.
Slide the flag on the funnel and remove the funnel.
Remove the mixer impeller.
Slide the flag and remove the mixer base.
Unscrew the screw securing the mixer frame.
Press on the frame catch and pull the motor out of the housing.
Disconnect the motor terminals and connect the new motor (red wire — plus, green — minus).
If necessary, the motor frame can be removed by unscrewing the two screws next to the motor shaft.
Reassemble the unit in reverse order.