Go to Settings -> Profile, click "Change Email" in the Email section, and Enter the new email you want to change to. A confirmation email will be sent to both your new and old email addresses. Just click the link in the email to complete the email change.
Please note: if you are changing your email address to an email that is already on file in Meshy, our system will not recognize it since it will be a duplicate. Make sure you use an unique email address to change it to, or change the email that you want to change your other account to on file to something else (e.g., add a "+1" in front of it to make it unrecognizable when you use the real email address).