Line the faceplate bushing up with beater shaft.

Align the faceplate's four outer holes along the four screws and push it against the machine.

Screw the knobs back on, once again in diagonal pairs.

If the beater bar does not let the face plate be pressed against the machine enough so that all four knobs can be reattached, then remove the face plate and re-adjust the beater bar to catch the driver plate.