romut on "Renaming category"

Hi all,
In order to improve my wordpress blog's CEO, I changed a category name. My permalink structure is: /%category%/%postname%/.

My problem is now, what do I have to do to route the old category name to the new one to avoid 404 errors. Said differently, I want all requests to URLs like <myblog>/oldcat/... point to <myblog>/newcat/...

Thanks.