Any way to change the door chime/alarm in a 94 civic?

If you remove the buzzer and carefully drive a screw into it from the top. You must do this while it's making noise. Once the screw touches the internal buzzer, it will muffle it. Another cool thing is to get a small bell or wind chime and tie it to the internal buzzer to get a ringing sound. These type of modifications may not be very reliable and are very difficult to accomplish due to the small parts involved. Worse case is you will damage the buzzer and need to buy another one... there are many on the market to give nice tones.