Measure the width of your cabinet's aperture. Subtract 1/8-inch from this measurement and cut both your top and bottom rails to this length.
Screw the top rail into place, being careful not to over-tighten the screws and bend the track. Lay the bottom rail slightly inside its future position but do not yet secure it.
Screw the sliding hardware to the top and bottom wooden doors. This varies between rail systems, but generally consists of small adjustable metal wheels, to be installed in the top and bottom corners of each door.
Adjust the bottom wheels to their highest setting, if adjustable, and hang the wooden doors from the top rail, one from each track. Slide the lower rail into position and slowly lower the bottom wheel settings until they snap into the track. Screw the bottom track into position.