How can I disconnect the alarm when the drying is finished?

Turn off and unplug the dryer. Since you need to remove the front panels and expose the electrical wiring of the dryer's buzzer you should turn the dryer off and then unplug the machine to avoid shocks. Once the dryer has been unplugged, turn its dial to the "on" setting to make sure the dryer is completely powered down.

Locate the buzzer. The best way to locate the dryer's buzzer is to check the machine's schematic or manual. The buzzer is usually located behind the front panel of the machine. In some cases the buzzer is located behind the dryer's back panel. Dryer buzzers are generally small black boxes that are wired to the timing device.

Pull the buzzer's wires. The most simple way to deal with a buzzer is to pull the wires that run into the buzzer. The wires should pull free with a firm but careful tug. Once you've disconnected the wires from the buzzer simply run a good amount of electrical tape over the ends so that no live wires are exposed. If you want to get the wires out of the way, tape the wrapped wires to the top or side of the dryer panels.

Test the machine. Once you've yanked and taped the buzzer's wires, plug the dryer back in and turn the machine on to test the buzzer. If the machine still buzzes at the end of the cycle then you removed the wrong wires. However, chances are that the machine will finish its drying with a quiet whimper instead of a loud buzz.