The first generation of the Muzik headphones (Muzik One) come with two sets of ear cushions. On-ear, and Over-ear. Gently pull on the cushion you would like to swop out while holding the ear cup with the other hand. The cushions are attached with magnets and should easily come off. Please make sure the cushion's seam is at the bottom (6 O'clock position).
The On-ear cushions are a little more low profile and is suitable for instance while working out or running.
The Over-ear are a little more comfortable for extended use, such as during a travel or while flying.
If you open up the Muzik Connect mobile application, you have the option to optimize the sound depending on whether you use the On-ear or the Over-ear cushions. Simply go to "Settings" and tap either "OVER-EAR" or "ON-EAR" from the "Ear Cushion EQ" option.