How to Replace Rungs on a Stair Banister

Measure the length of the rung before removing it. Write the length measurement down.

Place the blade of an circular saw an inch from the top of the rung. Depress the power button and push the blade with medium pressure through the rung to cut it away from the rail.

Twist the rung counterclockwise to unscrew it from the stair tread; many rungs are secured to the tread with a dowel screw. If it doesn't twist, pull up to unseat the wooden dowel, securing the rung, from the tread. Pry off the remaining chunk of the rung that is glued to the railing.

Glue the bottom and top half of the old rung back together with wood epoxy. This piece will serve as a guide, and will not be reused.

Lay the new rung flat down. Line up the bottom of the old rung with the bottom of the new one. Create a scribe line on the new rung to indicate the height and angle of the cut, using the top of the old rung as a guide.

Place the new rung on a flat work surface. Cut the correct angle on the top of the rung with a circular saw.

Look on the bottom of the new rung for a dowel hole. If there isn't one, drill a 1-inch hole into the bottom of the rung with an electric drill. Make sure the hole is centered on the bottom.

Twist the new rung counterclockwise over the dowel screw sticking out of the stair tread. If a wood dowel was used, just set the new rung over it.

Push the top of the new rung underneath the stair railing to dry fit it. If it doesn't fit, remove the rung and recut. Then replace the rung between the tread and railing.

Place a level next to the rung to make sure it is plumb.

Pull the top of the rung out from underneath the railing. Smooth wood glue over the top of the rung. Then push it back underneath the railing. Place a level next to the rung to verify it is plumb. Wipe off any excess glue with a damp cloth.

Tap two finish nails into the top of the rung to secure it to the handrail with a hammer.