One way to deactivate the alarm clock is to press the Menu (OK) key three times. After that, the alarm clock should be deactivated.
If this does not work or you want to be on the safe side, then follow these steps:
- Open Menu,
- Confirm "Alarm Clock" option with "OK
- Then, the word "Activation" comes up and there's a check mark next to it
- Confirm with the "OK" button until the check mark is gone and you have deactivated it.
It is important to return to the Home screen (with the red End Call key) in order to avoid placing the check mark again.