How to factory reset a Snom Phone
Using the handset
Hold down the # button while the phone boots up and wait until you see a two-option menu.
Confirm option one: Settings reset.
Using the web interface
Find out the IP address of the phone (press Settings then 6 then 2 to find this address e.g. 192.168.0.229)
Go to your phone's IP address in the web browser of your choice (HTTP authentication details are found on the Hardware page)
Click Setup and then Advanced.
Go to the Update tab and click Reset.