Find the small hole on your CD drive, it is usually near the button.
Step 3: Stick the clip into the hole
Stick the clip into the hole and gently push until the door opens.
Step 4: Finish
The drive opened!
To prevent this in the future keep your CD's clean and free of finger prints and scratches using some kind of CD paper sleeve or a jewel case properly stored in a CD rack. And make sure your discs aren't warped, because this may cause problems as well.