How do I connect the M720 mouse using the Unifying receiver?

Download the Unifying Software from http://support.logitech.com/software/unifying, make sure your M720 is turned on and a Unifying receiver is plugged in, then press and hold the toggle button below the display for 3 seconds until the LED on the selected channel starts blinking fast. Open the Unifying software and follow the on-screen instructions to complete the connection. A USB port is required, and the software is compatible with Windows 7, 8, 10 or later, Mac OS X 10.10 or later, and Chrome OS. (Page 5)