I have a website on aaa.com main domain. It's built mainly on pages, posts are used to represent news.
I created bbb.aaa.com subdomain (same server) and built a new website there. This new website should replace the old one (aaa.com). Old site can be erased, if necessary, the only thing I need is to preserve news. Meaning that there should be an "Old News" or "News Archive" button on new website, which leads to (all of the) news on old website.
Can you please let me know how can this be achieved, thank you so much.