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 22.214.171.124, 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 126.96.36.199.rom and click Upgrade
Once Rebooted, login and the Firmware version should now be: 188.8.131.52
On the Status Page if your Hardware Version is later than 184.108.40.206 then you can upgrade using the Over the Air Method, if your version us less than 220.127.116.11 you will need to use the USB Method, see below