Translate interface from Drupal UI

Needs revision -- Last peer review: 6 Jul 2013
Overview: 

Drupal is a content management system that is provided for people all over the world. As such, it is important that Drupal ships in as many languages as possible; however, many parts of the site still need to be translated into many different languages. The goal of the D8 Multilingual Initiative is to help expand Drupal to as many languages as possible. This lesson will teach you how to translate strings into other languages for Drupal.

Steps: 

Translate interface for non English language
If you have installed Drupal in a non-English language then you can translate the interface by doing the following:

  1. Go to: Administration -> Configuration -> Regional and language -> User interface translation
  2. Look for string you want to change or add a translation to.
    Note: The search is case sensitive.
  3. Make your changes and submit the form
  4. Test the changes you made by going to the page where this string was displayed

To edit an English language translation:

  1. Go to: Administration -> Configuration -> Regional and language -> Languages
  2. Click Edit for the English language
  3. Check the "Enable interface translation to English" checkbox
  4. Make sure your changes were saved by going back to Administration -> Configuration -> Regional and language -> User interface translation, and trying to translate one of default strings.

Note: If you installed Drupal in non-English language then you will not have English in Languages list. You will have to add the English language first by going to Administration -> Configuration -> Regional and language and using the "Add language" button.

Comments

in the second part,
it starts: edit english language, but from where?
Perhaps the lesson means to say
Administration >> Configuration >> Regional and Language >> Languages
admin/config/regional/language

and
the checkbox is "Enable interface translation to English"

Update status: 
Needs revision

If you has installed english language as default language you can't see the checkbox "Enable interface translation to English" this checkbox is hidden for the default language. I should add "Add a new language" and then edit it at "admin/config/regional/language" , before second part of this step.

Thanks for this step!