In Kukai, if you have lost your password, the only way to reset it is to use the seed words backup. This will generate a new keystore file, which will prompt you to create a new password. It is important to note that Kukai cannot reset your password, so it is important to ensure that you have your seed words backed up in a secure place. If you have not lost your password, then you do not need to reset it. However, it is always a good idea to have a strong and secure password to protect your account. Be sure to read the pinned message, as it contains important information on how to keep your account secure.