Quick way: Search Customer > Type their name > From their profile click "User Account" > Click "Send Customer Invite E-mail" > Choose "Customer Invite" template.
Type in the customer's name in the "Search Customer" box.
Click the customer's name:
Once you see their profile, click "User Account":
Click the "Send Customer Invite E-mail":
Click the "Customer Invite" template:
Step Six: Click "Send E-mail" and you're done: