Plan the layout of the stair balusters. You can install one, two or three balusters per step. The step relates to the top of each step or landing. Measure the width of the base of the baluster. After the step, measured from the rear to the front of the step and mark this measurement on the step. If you are installing a second baluster on the step, again measured from the first mark the center of the central baluster and place another mark in the center of the tread. For a third baluster, divide the total of the tread by four evenly spaced balusters in the first three quarters of the entire journey.
Inspect the bottom of the stair balusters to pre screws or pins inserted. If pins are not installed, drills a hole of 1 inch in the center of the bottom of the baluster. Place wood glue on a pin double-ended screw, and then screw the bolt into the hole.
Drill a hole of 1 inch in the center marks in step with a head tip of appropriate diameter to accommodate the pin or screw in the bottom of the baluster. Screw the stair balusters pin or screw into the hole in the step. Keep right next to the railing rung. Place a leveler on the side of the baluster to ensure it is upright.