re-attach geared pulley

re-attach stepper motor mount/bracket to the damper

Remember the screws you saved when removing the motor mount?

re-attach stepper motor bracket with screws from above

re-install pulley / tensioner to top of frame with thumb screw

re-tension belt

finally re-install the belt cover

Some people have suggested that this belt cover is not needed. It is possible that you could re assemble with one of the screws left over from replacing the damper to secure the damper to the mount.