HTML Email Templates

Hi,
I am trying to edit one of the templates using "HTML Email Templates" plugin.
When a new user sign up for my blog, I would like the welcome email start like this:
Hi (user's first name)
Welcome.....

And the email sent to admin start with:
Dear hard working ............team,
A new user has registered on your site, etc, etc.....
***********
Thank you very much in advance for your help :slight_smile: