With your browser proxying traffic through Burp Suite, log in to your account, submit the "Change email" form, and find the resulting request in your Proxy history.
If you're using Burp Suite Professional, right-click on the request, and from the context menu select Engagement tools / Generate CSRF PoC. Enable the option to include an auto-submit script and click "Regenerate".
If you're using Burp Suite Community Edition, use the following HTML template and fill in the request's method, URL, and body parameters. You can get the request URL by right-clicking and selecting "Copy URL".