Change Template For System email

I have a website that sends e-mails after a customer 1. gets an offer for their device [login to view URL] i receive their device [login to view URL] i inspect their device 4. when i pay them. I just need to change the template of the email for #1... #3 sends the email 2 times and #4 sends the email 3 times every time i change the order status from admin. I have already designed an html email template that will replace #1. So basically the job is: -Change email template for #1. customer gets an offer for their device -Fix #3 and #4 so it only sends one email Dont bother on high bids this isn't a hard job.