Customize login prompt in Login Plugin OAuth

Hi,
I have installed and set up the plugin to use OAuth with Google credentials and it works smoothly: this is a very fine and powerful plugin)
However I did not find where to customize the login prompt:

User Login
This page is restricted...
which is quite important regarding UX since this does get localized when using a language other than the default English.
Thanks for your help!

Ok, got it, I was looking in the wrong place, the bit I was mentioning is directly managed by the Login plugin (pages/login.md)... which needs a bit of localization)

Follow up request: the OAuth plugin combines 2 login methods.

1. the OAuth login via Social Networks
2. classic login with username and password

Having both is confusing to users if you only plan to use OAuth with the corporate Google account for instance. Could you please outline how to sanitize this login prompt without messing with the login plugins? I understand I will need to use inheritance but I am not sure wether I need to alter both the Login and OAuth plugins.
Thank you,