Head to Clock Town and climb up to the platform on the front of the Clock Tower. Now wait until 12:00 on the final day for the stairs to open up. Climb up the stairs for a cutscene. Now play the Oath to Order for another cutscene where Link gets teleported to the moon.
The Moon
Head up the hill to the big tree. There is a Feather Statue if you want to save. Now talk with the person wearing the Majora's Mask. Agree to play with him to be transported to another area. Walk forward some for a brief cutscene before a battle begins.
Majora's Mask Battle
Majora's Mask
Occasionally - Majora's Mask will turn sideways and start spinning towards you. Simply attack it with the sword to stun it. Now run over and attack it with the sword some more. Repeat this a couple of times and the other masks will start flying around the room.
Be sure to take out the others masks as soon as possible to make the rest of the fight easier. They can be killed using Light Arrows or reflecting Majora's Mask's energy beam at them. Now continue the fight as before until Majora's Mask is defeated. It will transform into Majora's Incarnation.
Majora's Incarnation
Majora's Incarnation will start running around the room. Wait for him to slow down and then shoot it with an arrow to stun it. Quickly run up and attack it with your sword. Be sure to shield should it start shooting stuff at you and repeat these steps until it is defeated. It will transform into Majora's Wrath.
Majora's Wrath
Majora's Wrath will attack you mercilessly using his long arms. Shield against them and shoot it with an arrow to stun the creature. Now run up and attack it with the sword. Repeat these steps and Majora's Wrath will eventually start doing other attacks. Just stun and attack it until the end.
Back to Part 9: Stone Tower Temple