1. Enable the locale module on the administer » modules page
   • administer > access control
   • give yourself (and any other roles that should have it) permission to access locale
2. Go to the administer » localization page.
3. Select the add language tab .
4. Assuming English, create a custom language by adding en-US in the Language code text field.
5. Give your language a name, such as custom-English (be sure not to use spaces in your language name), and add the language.
6. This will return you to the main localization page. Set your new language as enabled and as the default.
7. Save the configuration.
8. Then disable the original English language set (that is, unless you would like users to be given the option to choose between the two in their account area).

Now, any time you visit a page with Drupal hard-coded content, it will be added into your language set database.

Once you have visited a page that you wish to change the content:

1. Go to the manage strings page (admin/locale/string/search or /?q=admin/settings/locale/string/search) of the localization section.
2. Enter in the string you wish to search for.
3. Edit the result and enter your replacement text.