Orient the console so that the words "XBOX 360" on the sides are right-side up, and the faceplate is facing to the left.

Insert a metal spudger between the top vent and the top bezel near the rear of the Xbox.

Rotate the spudger away from the console, prying the edge of the fan vent up until the two plastic clips come free.

Be sure to rotate the spudger far enough so that the plastic clips clear the silver rim of the top bezel.