If I don’t have the installer login, can I still update the firmware, install a new communicator module and switch to your service?
To better help you, we will need a little bit more information about what security system you have. Specifically, what panel is installed at your location?
The bulk of the information that you are looking for to start service can be found here
2GIG-CP21-345E
Yep, this page will go over everything you might need in order to get started.
Installer codes and programming access are defaulted and opened up upon connection to service.