Log into the Admin Portal and navigate to the users tab.
Check to see if the user has a phone. If there is a phone assigned to the user, remove it from the user.
It will be helpful to copy down this information because you will need it later.
If there is no phone assigned proceed to the next step.
Select the user then go to Directory Services > Manage Services.
Disable CM Voice Services and Voicecube services.
Remove the number by selecting Directory Services > PropertiesYou will now have a new window labeled "User Properties." In this window Click the IP phone and select “none” and then click save.
From the locations tab select the location where the number is located and click on DIDs > Manage DIDs. A new window labeled Manage DIDs will appear on the right.
From this new window select the phone number (DID) you want to change and click the button labeled "Update."
Change the highlighted area to the desired extension (DN). Make sure this extension is not a number that has already been taken by another person before you change it. Click save when you are finished.
Navigate back to the Users tab and search for the user the DID was originally removed from. (Note: At this time the user has no DID, you will need to search by first name, last name or username) Then click on Directory Services > Properties.
In the new window labeled "User Properties" click IP Phone and select the DID from the dropdown and click the button labeled "Save."
the selected user will now have a new DN assigned and is ready to have their phone and services assigned back to them. (See links associated with Steps 1, and 2.)