When you buy an MP3 player, you will also get a USB cable which you can use to transfer music from computer to the device. Simply plug in the cable to both ends (one to the MP3 player and the other one to a USB computer port). If required, activate USB mode in the MP3 player's menu. The internal storage device will be available in My Computer from where you can copy and delete music. You just copy content from one directory to another.