To change the email content, you will need to be logged into the admin area.
On the left-hand side, scroll down to Content. Look for the option called Email Content.
You will then see all the emails available to edit.
Click Edit to see the existing email content.
If you scroll under the content you will see Available Tokens. These can be used to add a personal touch on the emails. If you use the token {{ firstName }} for example, it will add the customers first name that is stored in the admin area. The tokens are different for every email.
Once you hit save, your changes will take effect.