Hang each bypass door panel on its respective track and close the bypass doors. Place a piece of masking tape on each door panel's outside edge, the edge that butts against the door opening.
Remove the bypass door panels from the tracks. Set a bypass door panel on a set of sawhorses, keeping the side of the door with the masking tape facing up.
Measure up 36 inches from the bottom of the bypass door panel that is resting on the sawhorse with a tape measure, keeping the tape measure on the edge of the door with the masking tape, and place a pencil mark at the appropriate spot. Hold the end of the tape measure on the edge of the door panel at the 36-inch pencil mark and place a second pencil mark 2 inches in from the edge of the door.
Measure the diameter of the pull handle's nipple with the tape measure. The pull handle's nipple slips into the bypass door panel.
Equip an electric drill with a hole saw that matches the pull handle nipple's diameter. Many bypass door pull handles use a 2 1/8-inch hole saw.
Center the hole saw over the pencil mark 2 inches from the edge of the door. Cut through the bypass door's veneer with the hole saw. Do not drill completely through the bypass door.
Pry the bypass door's veneer from the door's core, using a slotted screwdriver for leverage. If the bypass door contains a solid core, pry the core from the area below the veneer cutout with the screwdriver.
Press the pull handle's nipple into the hole drilled in the bypass door panel. Drill the pull handle's hole in the second bypass door panel, using the same method used on the first panel.