-First help Luna Lovegood in the Clock Tower Courtyard. After you talk to her, use Wingardium Leviosa on a nearby bench and move it to the location of the small “X” next to the pear tree. Climb up and use Reparo on the roof. Then use Reducto on the “X” and levitate the Swamp Box down before climbing down. The box should be placed on big “X” near the fountain. Cast Incendio or Reducto and the Swamp Box will explode.
-Now head over to the Transfiguration Courtyard to help Ginny Weasley. Use Wingardium Leviosa on the Swamp Box after speaking with Ginny. You’ll then enter a Wizard Encounter with a few Slytherins. Defeat them and use Wingardium Leviosa on the Swamp Box again to move it to the big “X”. Use Incendio or Reducto to make the Swamp Box explode.
-Finally head to the Paved Courtyard and wait until Ron and Hermoine talk to you. Head up the stairs and along the path until you get to a broken pipe. Use Reparo on the pipe and then climb it, jump onto the ledge, run past the second pipe, and climb up the third pipe. Then jump on top of the roof and use Wingardium Leviosa on the Swamp Box to throw it off the roof. Climb back down to the ground and use Incendio or Reducto to explode the Swamp Box. Ron will then tell you that you’re done.