Overwrite default WordPress wording

I’m working on a plugin that changes the password requirements to be a bit stricter, however wherever there is a password field to create a password, WordPress’ hints are now no longer accurate (e.g. Password must consists of seven characters).

How can I replace those hints? Is there a filter/function that can help with this?

You can filter 'gettext'.

Sample code, not tested:

add_filter( 'gettext', 'wpse_65085_change_error_messages', 10, 3 );

function wpse_65085_change_error_messages( $translated, $text, domain )
{ 
    if ( 'default' !== $domain )
    {
        return $translated;
    }

    switch( $text )
    {
        case 'Hint: The password should be at least seven characters long. To make it stronger, use upper and lower case letters, numbers and symbols like ! " ? $ % ^ & ).':
            return __( 'Use whatever you want', 'your_plugin_text_domain' );

        // more cases here.

        default:
            return $translated;
    }
}