I've got a document with a style structure I'm satisfied with (visually). But now it turns out I should've included a Heading 1 level above what is currently my Heading 1 level...

Meanwhile, I found out it's possible to "ship" every title a level up, but that keeps the formatting at the original level. So a title that was Heading 2 is now Heading 3, but also looks like what used to be Heading 3, so the outlook of my entire document has changed...

Is there a way to "redefine" current Heading 1 as Heading 2 (keeping all formatting)?

Thanks for your insight!