most of them will trigger the panel tamper switch when opened and you will need the engineering code to disable the sounder while you swap out the battery. If you don't have this, I would suggest you do it during the day when most people are at work to avoid disturbance and put some blu tack over the sounder of the internal buzzer as this can be very loud.
Just make sure you connect the polarity correct on the new battery...normally its red to '+' and black to '-' or just mimic the way the old battery was connected. Just be careful when you take the panel cover off as there will be a lot of wires in there, so make sure you don't pull any accidentally from their terminals.