Enabling URL Redirects from Old URL Paths

Hi – The website I am currently working on was set up so that all pages follow the URL structure example.com/main-navigation/parent-page/page. I’d like to remove the “main-navigation” part of the structure.

I know I can do this in the Pages manager by un-nesting the pages from the “main-navigation” page, but I want to ensure that, if anyone had bookmarked a page, it would automatically redirect them from example.com/main-navigation/parent-page/page to the new URL at example.com/parent-page/page

How can I easily set up redirects for all these pages? It would be at least a couple dozen pages that would need to get redirected.