Nicest way to 301 Redirect traffic when changing permalink settings

Question

If I change my permalink structure, is there is a nice way to handle when people/bots go to the old structure?

I presume I can add use .htaccess and write a rule to redirect based on a 301 but is it possible in my case?

I currently have site.com/%year%/%month%/%day%/%postname% and I will just want site.com/%category%/%postname%

Answer 1

Dean's Permalink Migration has always worked for me. Install it before you change your permalinks.

Answer 2

For people, you can try Smart 404.

Answer 3

You can typically perform the 301/302 redirect in the fuctions.php file of your theme.

Here is one of many references you can find - http://perishablepress.com/permanent-301-redirect-via-php-or-htaccess/