Cut and attach Exterior Sheathing (OSB)

1: 34-1/2"x24-5/8"x3/4" OSB

1: 34-1/2"x7-3/4"x3/4" OSB

1: 71-1/8"x10"x3/4" OSB

Place assembled frame on table/ground with narrow stud-gap on right and window on bottom

Place tall strip over left stud-gap so that half the outer 2x4 of the window frame is exposed, and leave a 6" overhang along the bottom edge. This should leave a 1.5" overhang off the top and a 3/4" overhang off the left side. screw in at 16" spacing with 1-5/8" screws

Place smaller strip along the bottom leaving a 6" overhang off the bottom and butting up against right edge of first osb strip; screw in at 16" spacing with 1-5/8" screws

place remaining piece butted against right edge of first osb strip, and aligned with the top yielding a continuation of the 1.5" overhang at the top. the right edge should cover half the stud-face; screw in at 16" spacing with 1-5/8" screws