Unable to edit custom Header HTML for an event registration form web page

It appears there has been a redesign with Neon CRM, I have been through every menu possible and cannot locate where to edit the header on our event registration page. I can customize the event registration page but not the website header and menus, which are generated with Wordpress, but even in our Wordpress I cannot edit that particular header either. On the Neon CRM dashboard there is a set of directions giving this link on how to customize forms and pages, but the link is broken: https://z2.zendesk.com/entries/21452209-Customizing-Standard-Web-Forms. So, the only thing I can do until this issue is resolved is create a safe redirect in WordPress for that event so that anything coming from the form I cannot edit is redirected. Please help! Thank you, Kathy P.