This extension is an ocmod, to install it, simply go to the Admin side of your store and go to:
Extensions->Install
Then install the ocmod and refresh your modifications.

This extension creates stronger password requirements for registering a new account and resetting your password.

The requirements that Opencart defaults to are that your password can be no less than 4 characters and no more than 40 characters. With this module it requires at least 1 capital letter, 1 lowercase letter and a number. It also requires that your password is at least 8 characters.

Please send me a message if you have any issues installing this modification.