Change text "Hi [user]" in email.

After placed an order, the customer receive a short summary.

How can I remove the write:

"Hi [user]".

Bacause the greeting is a bit unformal and it doesn't fit to all website.

So, I want remove the greeting or at least use a formal: "Dear [user]"

Hi,

You can use a translation override in order to change that:
www.hikashop.com/download/languages.html#modify