Editing Email Templates

I'm a bit confused as to how to use the email template editor.

Example, when I try to edit "back in stock notification" The body consists of this

{{ snippet("header", {"title": product.name } ) }}
{{ __("hello") }},


{{ __("back_in_stock_notification_header") }}


{{ product.name }}


{{ __("back_in_stock_notification_footer") }}

{{ snippet("footer") }}
However the preview shows:
Hello,

We are writing to inform you that the following product is back in stock in our store:


Welcome to purchase!

Where can i edit the text? I cant find where it says "We are writing to inform you that the following product is back in stock in our store:" so how can i change this text?

Administration->Languages->Translations->Search for string and replace with whatever you want.