Steps  to disconnect or unpair a Bluetooth accessory from your iPhone 8:

• Go to Settings > Bluetooth on your device and turn it on. Stay on this screen until you've finished pairing your attachment.
• Wait for your accessory to appear on your device after putting it in discovery mode. Check the instructions that came with your accessory or contact the manufacturer if you can't find it or aren't sure how to make it visible.
• When your accessory's name displays on the screen, tap it to pair it. It's possible that you'll need to enter your PIN or passcode. Check the paperwork for your item if you don't know what your PIN or passcode is. 
• To remove a Bluetooth item from your phone, go to Settings > Bluetooth, identify the device you want to remove, hit the details button, and then tap Forget this Device. This will delete the attachment from the list of Bluetooth devices that are available.

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