The pegs are tapered so to change your tuning pin, remove the string and place your tuning wrench over the string end of the pin. Then tap on the wrench to tap the pin out through the harp arm. Replace the pin by inserting from the tuning side. Place the tuning wrench on the tuning end of the pin and tap it into place. The tuning ends of the pins should all be aligned. If necessary, wooden toothpicks make great shims.