Well, you need to know what the item is on which you are trying to reactivate the door beep. One assumes it is an alarm - but you didn't say.
Once you work out what it is, the next step will be to suss out the make and model - but again, you didn't say what that is in your question, so we are flying blind.
Once you have worked out what you have, you can look for the manual - often available online with a simple Google search and a bit of digging.
If you can't get any joy doing that, come back here and ask, with a full set of information. You may also come across more dedicated forums dealing specifically with alarms
belp, November 2016
