The Email Address for your Tindie Profile can be updated within your profile settings.
Start by clicking your Username on the top right of the page to open a drop-down menu. From that Menu, select Update Profile.
In your profile, look for the Email Settings section and click the Gear Icon to edit your email address.
Just enter your new email address as well as your current password in the appropriate fields.
Once you're finished, be sure to click the SUBMIT button at the bottom of the page to save the changes.
After you've submitted the new email, a confirmation will be sent to the address. Be sure to open the email and click the link or copy and paste it into your browser to confirm the changes and complete the update.