Hey Kathelijne, thanks for posting! While you're in the drag and drop editor, you won't be able to make edits to the footer of your template. The drag and drop editor is only meant to make changes to the user editable area in the middle of most templates, and since some of the elements are required by federal law, we keep them hard-coded.
Depending on your account time, there are a few ways we can edit the footer text. Let me know the username you use to log in, and I'll take a look at your account to see the best way to get that done!