How to convey the user that some of the form fields cannot be changed later?

I have a form wizard some input fields. On the first step of the wizard, there are 2 checkboxes which once the form has been submitted, cannot be edited. All other fields can be edited later on if the user wants to.

How do I tell the user that the two checkboxes cannot be edited so that they do not miss out on the message? Is the following message understandable?