Forgot password: enter your e-mail when logging in the O365 portal and click the "Can’t access your account?" link.
Change your password on O365 portal: My Account >> security and privacy >> password, or use this direct link: passwordreset.microsoftonline.com .
After you change your password, please do not forget to set your new password on ALL your devices (telephone, tablet, laptop) otherwise you can be locked out from your account.
Still have problems logging in? Contact computing@ibs-b.hu.