Go to Admin > Edit - your account name.
From the password complexity section, set the password settings.
Enforce History: controls how frequently a user is allowed to reuse a password. The value sets the number of times are user can reuse a previous used password. By default, set to 0 (zero) which allows reuse of previous used passwords, and can be set to 0 to 24.
Maximum Age: controls the number of days a password expires. By default, set to 0 (zero) which a password never expires, and can be set to 0 to 999 days.
Minimum Length: controls the minimum number of characters required for a password. By default set to 8 (eight) characters, and it can be set to 0 (zero) which will not require a password and is not recommended.
Password must meet complexity requirements: controls the type of characters required for a user password. When enabled, a password is required to contain a minimum of 3 (three) characters from either of the five categories listed.
To apply a setting change, select Save.