Hi @polvolula,
All of these can be changed by using M2 shortcodes, what you need to do is go to Membership 2 > Settings and click on Edit for your protected content page.
In that page replace existing content with this:
[ms-protection-message]
[ms-note type="warning"] PLEASE_LOGIN_CONTENT [/ms-note]
[ms-membership-login show_note="no" label_username="USERNAME_LABEL" label_password="PASSWORD_LABEL" label_remember="REMEMBER_LABEL" label_password="LOST_PASSWORD_LABEL" label_log_in="LOGIN_BUTTON_LABEL"]
I’ve used capslock for placeholders so you now need to replace those with your own text and that should be it.
Cheers,
Predrag