Measure the distance between the two walls in your closet that the rod will span.
Make a mark indicating where you will install the top rod. Normally you install top rods about 65 inches above the floor. Raise that height by reinstalling the top rod 6 to 12 inches higher, if possible, to give you more vertical hanging area for both rods. Mark the spot to install the lower closet rod, approximately half the height of the upper rod.
Install closet rod brackets on one side of the closet at the two heights you marked off in step 1. Position the bracket in place and affix it to the wall with screws. Fasten it to the wood framing studs in the wall or the wood hook rail that is installed in most closets at about the height of the upper rod.
Tape a small level to the closet rod. Insert it into the top bracket. Determine the point on the opposite site of the closet to attach the closet rod by adjusting the height of the rod until the level reads level. Mark the spot with a pencil. Repeat, using the lower rod.
Attach both the upper and lower closet rod brackets to the other side of the closet at the spots you marked in step 3.
Place the rod in the brackets.