The part he calls little buzzer will look very similar. Always plastic with metal visable through hole in top(probably through hole mounting as well). Find it unscrew board it's on. Put your finger on it as u hold it and flip board over, look through at your finger, see two solder points? You have an iron, solder and Flux right? Flux it get some leaded solder and melt some into each point. If they used lead free it 1)melts at higher temp 2)wont allow as long to remove 3)might be myth but old solder joints don't flow nice so let's just not take the chance. I'd bet if u can clip the board with buzzer down and do as I say it will drop right off after adding leaded and then put the iron on each point. Alternate rapidly... Point is make them both liquid at the same time. There is a solder called low melt alloy that gives u a lot more time and is great with ics and lots of pins. I doubt u will need it here but it would make life easier and if u are looking for a bit of kit buy some and you will have it left for next time. Hope you figured this all out on your own but incase the. Ext person...