c5c How to open or reprogram c5c without e-mail

Hi
How to open or reprogram c5c without e-mail because the e-mail that my brother and brother is missing and do not know his e-mail

http://cloud.help.mimosa.co/unlock-process

If you don’t have the email that was used to unlock the radio, you will need to provide Mimosa Support with proof of purchase. Please contact them at https://mimosa.co/support