To install entry door side panels, detach the door from its frame, place the jamb containing the side panels appropriately in the opening, add shims as required, and nail the jambs to the studs. Ensure that the jamb is straight and level, and reattach the door to its frame.
To detach the door from its frame when installing entry door side panels, tap at the bottom of the hinge pins using a nail set and hammer. Keep the door safely aside.
Then, drill holes at the required positions in the jamb for securing it to the door opening. Position the jamb containing the side panels at the center of the front door opening. If the jamb is split, position one of its parts in the opening.
Now, position door shims between the wall studs and the jamb, and nail the jamb in place using the holes drilled before. Ensure that the nails go into shim and the stud. Attach the jamb at one place in the opening.
Next, use a level to ensure that the jamb is plumb. Place one more door shim on that side of the jamb where the previous shim was placed. Nail the jamb in place as before.
Place a level over the jamb's top, and check if it stands straight and is square with the side that is plumb. Then, attach the top portion of the jamb using nails as before. Finally, attach the door to its frame using the hinges, and affix the required hardware.