E commerce website SEO Question, I am Planning to change the URL of my Products pages of the site?

[Kevin]

Eg: My Current url is http://www.mywebsite.com/buy/abc.aspx
My New URL would be http://www.mywebsite.com/abc.html

Can any one please help me on how can i minimize my Loses (in tems or traffic and rankings), because lot of linkbuliding has been done for my old page

And 1 More thing i don't want to continue with/buy URL in future, how do i get rid of it (how do i demote it/replace it with current URL)

[James]

Redirect it to 303. When any one type urn old URL then it redirect to the new one URL.

[Olivia]

Every SEO face this problem normally. If you give a URL tahn you want change this url, you keep tweaking and tweaking until you get it just right. Fast-forward 2 months – you’re sitting on 17 layers of 301-redirects, you haven’t done any link-building, you haven’t written any content