Step 4 · Install Door Jamb and Door
Assemble the door jamb (sides and head) according to the pre-hung door manufacturer's instructions. Insert the assembled jamb into the framed opening, ensuring it is plumb and square. Use shims between the jamb and the framing to achieve a perfect fit and to hold the jamb in place while you secure it. Screw or nail through the jamb and shims into the king studs. Once the jamb is securely installed, hang the door slab onto the jamb hinges.