Modify/Alter Password Policy Constraints Text
Short answer:

Of course there is a module for that.

Actually, more than one:

https://www.cmsdrupal.com/blog/how-implement-custom-password-policy-drupal
https://dev.acquia.com/blog/password-policies-and-drupal/03/04/2017/17856

Longer answer:

Since you don't just want to change the policy (you want to change the form markup too) you might also need to use hook_form_user_login_block_alter(&amp;$form, &amp;$form_state, $form_id).