Browse to the IP Address of the phone (to find the Base?s IP Address tap the button on the top of the base and on the Handset screen you will receive a paging with the IP address).
Login to the control panel, the default username and password is admin
On the status page check if the Firmware Version is older than 220.127.116.11, if so complete the next step
Click Phone, then Upgrade.
Click the Browse link where it says “Select and Upgrade Base Firmware” and locate the file 18.104.22.168.rom and click Upgrade
Once Rebooted, login and the Firmware version should now be: 22.214.171.124
On the Status Page if your Hardware Version is later than 126.96.36.199 then you can upgrade using the Over the Air Method, if your version us less than 188.8.131.52 you will need to use the USB Method, see below