Measure the length needed for your brace from a metal stud, or scrap, of the same size using a measuring tape.
Scribe a line at the required length using a metal scribe.
Cut the length at the scribed mark using a hack saw.
Install the brace diagonally between the horizontal and vertical sections of the framework. The sides of the brace should overlap the sides of the frame.
Drill a 1/4-inch diameter hole through the four sides of the brace and frame using a drill fitted with a 1/4-inch steel drill bit.
Insert a 3/16 bolt in each of the four holes from the outside of the brace.
Install a lock washer onto each bolt from the inside of the brace followed by a nut. Turn the nuts clockwise by hand until snug.
Tighten the nuts using two adjustable wrenches. One wrench holds the head of the bolt as you tighten the nut clockwise.