Canon MultiPASS C50 User Manual page 270

3. Insert the plugs with the handset cradle in the holes on the unit.
N
If you have difficulty inserting the plugs, turn the unit so that the left
side is facing you and the right side is placed against a wall. This will
allow you to insert the plugs without the unit moving.
4. Insert the screws into the plugs and push them in with your finger.
N
If you cannot push the screws in with your finger, use a phillips
screwdriver to push them in. (Do not screw them in as the screws
may break.)
Make sure the screws are inserted all the way into the plugs.
B-4
Options Appendix B