If necessary, use the utility knife to cut a small hole in the rim strip behind the spoke nipple.

Loosen the spoke nipple using a 7 mm wrench.

Remove the spoke.

Replace the spoke.

Installation is the reverse of removal. Tighten the new spoke into the nipple.

Be sure the spoke is laced into the wheel in the same way as the one that was removed. Make sure it goes under or over the one next to it as necessary. Look at other sets of spokes on the wheel to determine the correct orientation.