Swing the alternator up and then snug-up the upper bolt to keep it from moving while you’re removing the pulley retaining nut. Use a 24mm socket attached to a 1/2” drive air impact wrench to remove the pulley nut. Install the new overdrive pulley and secure the nut with the impact driver.
Use the 15mm socket to completely remove the lower alternator mounting bolt.
Lower the alternator back to it’s original position, insert and tighten the lower bolt you removed earlier as well as tightening the upper mounting bolt. Use the 15mm wrench to release the tension on the belt and slip it onto the new alternator pulley.
Slip the plastic cap back on the pulley retainer nut, replace the alternator cover, close the hood and the job is done.