Safewatch Pro 3000 - replace broken Wireless Door/Window Transmitter

Hello experts - I have purchased a new "5816WMWH" Wireless Door/Window Transmitter to replace one that was on my back door (the most used entryway) of my house. The old device was on zone 13. Please can you advise whether I now need to un-enroll the old unit - and if so, how, then how to enroll the new unit to zone 13. Is there a way to simply overwrite the serial number or do I need to completely remove the entry in the system for the old transmitter then completely enter all the settings for the new transmitter. If I have to re-enter everything is there a way to review how the old one was setup so that I can duplicate everything (except the serial number) exactly? This is all very new to me - so please "dumb down" the answer, if at all possible! Many thanks.