Quote from Scawen : 1) Visit details page
2) Click "send email to set new address"
If you can't access your existing email address then you need to wait a week after clicking that link, then you can proceed without access to your old email, to set a new email address.
3) Wait one week and come back to your details page, you will see a link to proceed.
It's the only way we can prevent license thefts. It is very important to make sure your LFS email is up to date.
Please do not ask technical support for help. Geraldine cannot help with this, she would have to email the old address to make sure the existing owner hasn't had their account stolen, then give them a week to reply. We have an automated process in place to do that. She doesn't have the time for this. It is your responsibility to keep your email address up to date.
https://www.lfs.net/forum/post/2131136#post2131136