Use your thumb to depress the LEFT ear pad near the long outer edge, creating a gap between the cushion and the frame. (The right ear cup is pictured, but the process is identical for the left ear cup.)

Insert the flat end of a spudger into the gap you've created, between the edge of the cushion and the frame.

Pivot the spudger down to unclip the long edge of the ear pad.

When the first clip disconnects, you'll hear an audible clicking sound.

This may take a considerable amount of force. If the cushion won't click out of place, move your spudger to different points along the long edge.