How to Change Wordpress Permalink Without Lost Backlinks

I created this website using Wordpress since 2003. From the beginning, I change some features in the website, including upgrade the Wordpress engine. I also use this website as my personal lab. I tested all features in the web and try to figure out how to optimize them.

Then I tried to change permalinks. I just want to change my permanent link like:

http://www.wahyu.com/2005/10/11/me-procrastination/
to
http://www.wahyu.com/me-procrastination.html

The problem is, some of my friends already linked to my post, so I can lost my back links. Then after search some resources, I got the way to change permalinks without lost backlinks.

I change the setting in my wordpress at menu Settings - Permalinks



I use 301 redirect by changing .htaccess:

RedirectMatch 301 /([0-9]+)/([0-9]+)/([0-9]+)/(.*)/$ /$4.html

You can try them using your current setting. But be careful to backup your .htaccess, so you can recover them when something wrong.