Nubee question about replacing an old site

If you are using Apache for your webserver, RapidWeaver has a built-in editor in the publishing settings for something called the htaccess file.
In the Apache htaccess file, you can use something called a redirect.
So you can forward any requests for the old URLs to the new URLs.

You should put together a spreadsheet “mapping” all the old URLs to what will be the new URLs (including the download links)

Then simply create the htaccess rules