Complex sentence: To put music into the device, the music first had to be encoded in the mp3 format by an encoder provided by the user, and then transferred via the parallel port to the docking station that connected to the portable player device.
Split into simpler sentences: To put music into the device, the music first had to be encoded in the mp3 format by an encoder provided by the user. And transferred via the parallel port to the docking station that connected to the portable player device.