Updating Urls

I am trying to update a number of product URLs - just adding a few missing letters and stuff like that.

That worries me, since I dont want people to googlesearch the products and be directed to 404 page.

I've tested it on one product, changed one letter in the URL and its been a week and google still hasnt reindexed this and if you search it on google, its as high in the results as before, but it leads to 404 page.

How do I force reindexing? Shouldnt it be taken care of by the SEO addon and sitemap?

I am assuming that reloading the WHOLE sitemap in google webmaster tools would be a distaster as the whole website would have to be reindexed from scratch.

Am I missing something?

I can't wait for Google to spider my changes so I purchased THIS ADDON that allows me define 301 redirects right in the admin interface. But prior to that I included 301 redirects into the .htaccess file with code something like this:

RewriteCond %{REQUEST_URI} .*\/old-SEO-friendly-page-name.html
RewriteRule ^.*$ http://www.mydomainname.com/new-SEO-friendly-page-name.html [L,R=301]

This way you don't lose the traffic to a 404 - and eventually Google detects the 301 redirect and will re-index the new URL.

Google will drop the old URL's when it feels necessary, you'll see these in Webmaster Tools. It will also index the new URL's when it feels like it. It may even index both at the same time and lower the ranking of the new URL, because the page content already exists (existed, but as far as Google knows, it still exists), hence the need to 301 redirect the old URL's.

4Sprung have a pretty complex addon which Don has linked to, which is more of an 'all in one' type solution. CS-Cart Rocks also have an addon here which will allow you to set up the redirects within the Addons tab of a product/category/page.