Replacing an older motion sensor on my GO!Control system. Dates back to year 2000 with original ADT gear. Has low battery now, of which I’m aware, but am using this occasion to just replace the whole unit, as it often times never triggers at all, even under test. Have a 2GIG-PIR1-345 in transit now; hoping to receive by 9/5/17. Question: Do I delete the old sensor point from the GO!Control program, and replace with new, or can the existing point just be modified to accept new equipment? No idea what the “model number” would be of the old sensor; picture attached. Also, please direct me to appropriate tutorial for RF sensor replacement - this will be my first shot at doing one. DIY indeed! 
You can simply edit the fields of the existing detector to match that of the new one. Sensor programming is simply telling the panel when sensor ID and loop to listen to, and how to interpret the data.
You can find programming instructions for the PIR1-345 here.