Permalink migration to /�tegory%/%postname%/

I did read 1 post about permalink migration
http://www.deanlee.cn/wordpress/permalinks-migration-plugin/#comments
I’m not sure if it is a stable and safe plugin

Please advise

How to change permalink migration from /%year%/%monthnum%/%day%/%postname%/ to
/%category%/%postname%/ ?

Thanks !