This is one of idea how to make buzzer.

Dear friend,

For make this project you are necessary:

 - 2 x Resistor for 1KOhm;

 - 1 x Buzzer from Microwave, PC, Refrigirator or similar;

 - 1 x NPN Transistor like 2N2222 or similar;

 - few harnes.

Good luck!