> I read through a ton of them.
Did you read the mod_rewrite documentation at apache.org? That's the best way to get started, or at least to focus your questions... Links to those docs and to other useful resources can be found in our Apache Forum Charter. Examples can be found in our Library. Links to the Charter and the Library are at the top of this page.
Assuming that you wish to rewrite requests for the URL-path /product_info.php/products_id/287 to the script at the server filepath /index.php?product=287, then all that is needed is something like:
RewriteRule ^product_info\.php/products_id/([0-9]+)$ /index.php?product=$1 [L]
I assume that you intend to put this code into domain.com/.htaccess. If not, please let us know.
This further assumes that you already have other working rewriterules. If not, you will need either both of the following lines or only the second one, placed at the top of your RewriteRules. You may either need the first line to prevent your server from throwing an error, or the presence of the first line itself will throw an error. This depends on your current server configuration, and the easiest way to find out is simply to test it with and without the first line.
Options +FollowSymLinks -MultiViews
RewriteEngine on
Note that there is really no reason to use "/product_info.php/" in your URLs -- Using just "/info/" or "/products/" would work just as well, and be a bit shorter and a bit more memorable as well. You don't actually need to have anything in that "virtual directory-level" of the URL at all, unless there are other "products_id/<number>" URLs in a different "virtual directory-path" which
should NOT get rewritten.
Since you are apparently making a URL-format change now, consider making that change as efficient/effective as possible.
Jim