1. Cut out the bottom plate from the door opening.
2. Cut the door frame pieces from 3/4″ × 4 1/2″ (actual dimension) cedar: cut the head jamb at 61 1/4″ and the side jambs at 81 7/8″. Assemble the frame by screwing through the head jamb and into the side jambs with 2 1/2″ deck screws.
3. Cut 1 × 2 stops and install them inside the jambs with 11/4″ deck screws or 3d galv. finish nails. If the doors will swing out, install the stops 2 1/4″ from the outside edges of the frame; if they’ll swing in, install the stops 2 1/4″ from the inside edges.
4. Install the door frame in the rough opening, using shims and 10d galv. casing nails. Make sure the frame is square and plumb.
5. Cut twelve pieces of 1 × 6 tongue-&-groove boards at 81 3/4″. For each door, fit together six boards with their ends flush, then mark the two end boards for trimming so that the total width is30″. Trim the end boards.
6. Cut the Z-brace boards following the DOOR ELEVATIONS. Lay the doors on a flat surface and attach the brace boards using construction adhesive and l 1/4″ wood screws.
7. Install the hinges and hang the door, using shims to set the gaps at the bottom and top of each door.
8. Install flashing above the door, nail-off the siding, then install the 1 × 4 door trim, using 8d galv. finish nails.