Sorry to hear that the email about how to set up your lifetime service is missing! In late October 2015, we sent each backer an email with the subject titled, ‘Subscription link’ from firstname.lastname@example.org. For many people using Gmail, the email went into their “Promotions” section (if using a desktop it is a tab at the top of your list of emails in Gmail).
If you are unable to find it, we can resend it. Please contact email@example.com if you need more help.