How to reset Mater code on Safeguard Plus?

I just bought this foreclosure home with a ADT SafeGuard Plus system. I know it is old but I cant afford any more monthly obligations. I do not have any of the codes to operate the system. Is is possible to reset so I can use the alarm system and if so then how can I do this? KInda desperate as I am a single mom living in a inner city area. Thank YOU!!