Installing an USB/SD/MP3/Aux-in adapter on the Suzuki Jimny OEM Radio

The OEM Clarion Radio that comes with the Suzuki Jimny doesn't allow modern media inputs as most of the car radios. It comes only with a CD player and a AM/FM receiver. Replacing this unit with a convencional 1 or 2-din stereo is not that simple since the dash has an unusual round edges hole. Fortunately the manufacturer of the radio, Clarion, included a CD changer port called Cenet (anyone uses a CD changer nowadays?)