Simply slide the Earlum onto your ear. The best place to do this is to put it on at thin edge of the ear, towards the top.
Slide the Earlum down until it fits comfortably over the cartilage. Depending on the fit to your ear, you can either squeeze or open it slightly so that it fits securely.
Once you have adjusted the Earlum properly to your ear, DO NOT open and close it to put it on and take it off. Simply slide it on or off at the thinnest part of your ear.