1. Connect the Dongle to the computer.

2. Download the relevant installation package from here, make sure to select the newest version for your model. 

3. Find and extract the file dongle_52820_upgrade_vx.x.x.exe from the installation package, or in case you are upgrading on macOS, unzip the NRF52820_Dongle_update_CS80D4_XXXXXXXX file from dongle_mac_52820_upgrade_vx.x.x.zip. 

4. Double click on the upgrader executable to start the upgrading process. Under Mac OS, you need to unblock the app by going to 'System Preference' within the Apple menu at the upper left corner, then choose Security & Privacy, click the lock icon at the left corner of the window,  authenticate with your Apple ID, then click 'Open Anyway' to unblock.

5. Click the 'Start' button in the upgrade window, a progress bar will appear, wait for the progress bar to reach 100%, the status text within the window will change from 'Upgrading' to 'Upgrade completed'.