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There are several ways to eject the disc. The common methods are, click on the disc icon in desktop/finder and press Command and E
Or click on the disc icon in Desktop and click and drag it to Trash and Trash will turn to eject icon, so release it there.
Or restart your mac and immediately hold down the LEFT mouse button or left trackpad button before the chime sound/grey screen appears. Keep it held down until the disk comes out. It would like take only up to 20 seconds to eject the disc.
These methods will eject the disc unless the disc is jammed in there. Let me know if you are unable to eject it, so we can try a different method to eject it.
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