Yes, the instructions for the Module will be all that is needed for physical installation, it is a pretty straightforward process. If your 12VDC battery is particularly old you may want to replace it at the same time.
In the instructions, ignore the steps regarding account setup, as these are written for dealers. You will be activating your account automatically through our System Manager.
Finally, should I cancel ADT before or after I do this? I’ve heard stories of panels being disabled.
I cannot really give advice regarding cancelling of another service provider but I’ve not really heard of such a tactic being common. If you are concerned you could wait and cancel after. Since you are removing the existing communication equipment and using a new module there is nothing stopping you from just swapping the equipment first.