In the end, you need to add 301 Redirects to the server or the WordPress instance. It's much better to add them at the server level, so here's the 2 possible ways to go about this:
- RewriteRule patterns within .htaccess file.
The pattern is SUBSTANTIALLY like:
RewriteRule ^/product-1-page/ https://example.com/collection/product-1-page/ [R=301,L]
RewriteRule ^/product-2-page/ https://example.com/collection/product-2-page/ [R=301,L]
- Use the Redirection by John Godley plugin for Wordpress
- Note: This is for Cloudways, which uses Apache and .htaccess files. If you're using nginx, caddy, or another web server, the setup is different.
I would also suggest individual redirects that map your privacy policies, terms+conditions, disclaimers, anything else that may have been sent to a customer in a previous email, etc.
Besides individual product page redirects, you'll also want to add a redirect for the entire remaining site.
Be careful with (and test) all of this if you have trailing slashes, need access via http:// (which you shouldn't becuase you're only accepting secure https:// connections ;-), and other issues that might cause issues or infinite loops.
When it's all working, remove your old sitemaps submissions from Google Search Console and Bing Webmaster Tools and submit new one(s).