How to Replace a Baluster

Drill two 1/16-inch pilot holes into, and square to, the baluster's angled end and out the upstairs side. Coat that end with wood glue, fit the baluster into its tenon, and drive 6d finishing nails up through the pilot holes and into the handrail. Set the nailheads with a nailset and cover with putty. Nail the end cap back onto the tread.