If paired using Bluetooth:

On Windows:
To unpair your mouse from your computer’s Bluetooth:

1. Look for Bluetooth settings on your computer.
2. Find your device in the list of connected devices.
3. Click Remove device.

NOTE: If you want to create a new pairing, you'll need to perform a long-press on the Easy-Switch button on the bottom of the mouse. This will put the mouse into pairing mode.

On macOS:
To unpair your mouse from your computer’s Bluetooth list:

1. Open your Bluetooth preferences and find your device.
   
   
2. Right-click on your device and then Remove or Forget.
   
   

If paired with the Unifying receiver:

To unpair your mouse from your Unifying receiver:

1. Open Logitech Options, and click Add devices in the bottom left corner.
   
   
2. Click Add Unifying device.
   
   
3. Click Advanced.
   
   
4. Select the device you want to unpair in the list.
   
   
5. Click Unpair.
   NOTE: When you unpair the device, it will no longer be connected to the receiver. You will need to create a new pairing using either Bluetooth or the Unifying receiver.