How to replace the XER 10 my own equipment

I am looking for any up to date information on replacing the XER10 with my ubiquiti UDM. The buried fiber was just connected. I had to get through the AI bot with a safety issue for them to finally send someone for that. The technician did not know anything about routers. I called again and the humans on the phone do not understand why I am trying to replace the working router. I have even got messages from the AI and a human asking do I still need a tech to visit because the internet is working.

I currently have the Wifi turned off and a DMZ set for my UDM on the XER10. My UDM reporting a double NAT.

Do I need a tech to visit or can this be solved online?

Thank you.