Just "Inherited" Brinks System & Want to Know Options

["RZ" <SPAM@xxxxxxxxxxxxxxxxx>]

Hello.

I have just purchased a new-to-me home and it came with a Brinks (wired)
alarm system.  Don't know the age of it but it has to be 6 years old or
less.  I'm not interested in signing up with Brinks' service ($35/mo) but
have read that I will probably have to replace several components if I want
to be free from Brinks and still use it (with or without another service).

Is this true?

If my only option is to replace components (keypads (2), controller (?),
etc.), what would be the process involved and where/which components do I
need to replace?

I work in the computer industry so am comfortable with wiring, PCs, etc. but
am just learning about alarm systems.  The current alarm system consists of:
- 2 Keypads (Brinks)
- 1 Glass Break Sensor
- 4 Door Sensors
- 1 or 2 Smoke Sensors
- 2 or 3 Heat Sensors
- Controller Box (?)
- Battery Box (?)
- Relay Box (?) near 2nd Keypad
- Alarm Horn in attic
- Alarm located in HVAC return register

I would appreciate any and all suggestions for my situation.  Though not
required, if the expense was not too high, I would be interested in
connecting the system to a PC for whatever control this would provide.

Thanks!