Measure the distance for the opening. Measure to the studs that are closest to the outer edge of the hole you want to make. Record the distance on a piece of paper and mark an “X” on the studs that span your distance.
Cut two headers that are 2 inches thick and 12 inches wide to the length for your header. Long spanning headers must be thick to properly support the weight of the frame once you install them.
Remove any nails from the studs with a claw hammer in the area you install the header. Balloon framing has the studs go from the floor to the top of the frame, so make your way to the bottom of the frame to remove the nails -- before you go to the top of the frame to remove those nails.
Tap the studs near the top with a rubber mallet to push them out of the frame. Set them in a dry space.
Lift the first header with the help of other workers, so it sits snuggly between the studs with the “X” marks. Position it on the stud so it's against one side of the vertical studs, leaving room on the other stud for your second header. Raise it high enough so the bottom of the header sits where you want any openings in the frame to end.
Hold it in place while two workers hammer through the sides of the studs and into the header. Use at least three nails to keep the header securely in place. Secure the second header over the first, nailing it in place the same way you secured the first.
Fix short pieces of stud between the top of the frame and the top of the header. Space the shortened studs 16 inches apart like the regular full-length studs. Nail through the sides of the studs at a 45-degree angle to secure the short studs to the top of the frame and the top of the header.
Place one short stud at the top and bottom corners of the header. These short studs will rest right against the studs bracing the header in place, adding extra support to the header. Drive a nail through the short studs into the longer studs at 1-foot intervals.