ADT Security System Question

I am currently working with an ADT Safewatch Pro 3000EN.

All i need to do is delete a zone. We used to have a window in a part of our house, but, no longer have one. Therefore, the Zone is no longer needed.

I called ADT and they won't tell me how to do it over the phone. They want to send a technician out and charge me $135.00. I am sure it is just a few key presses, but, I can't find anything on google. I have the manual and that won't even say how to do it.

Does anyone out there know how to do this that may want to assist me?

Any help would be appreciated

TL;DR - I need to remove a Zone from my home security system.