How to deal with internal links in blog while developing new site in WordPress?

I have a client for whom I’m developing a new WP site. Their current site uses DNN but due to security reasons (among others) they have chosen WordPress. As we are migrating and updating blog content there are many internal links pointing to pages in their old site. Their url structure is: https://www.example.com/resources/blog-name/title-of-post However in…