I would redirect the entire domain using a 301 Permanent Redirect. Then check your backlinks and notify everyone you can that you have switched domains.
If you have any further questions, you can also
see what Google says by looking at item 4 on that page.
When you're ready to make the change, follow the instructions by minstrel. Since you're on a unix server, a simple redirect in the .htaccess file will do just fine.