To get to the programming, you must enter the passcode from extension 20. Normally, there is a DAB type phone at x20, which is what you need so you can press the extension number you are trying to change. Once you have the proper extension number, you can FWD through the programable options until you see "type". If you flash, you are exiting the particular program for that extension. It has been awhile since I have worked on one of these!!! I can help with the password if you need.