You need to be at the Home page. Press Home, then press Del (to get a search box), then enter the commands into the search box.
I just tested my own instructions above on my 2.5.8 DX, and they worked for me.
If you are doing these things in this order and it is still not working, please provide more details so we may be of more assistance to you.
Last edited by geekmaster; 12-14-2011 at 11:45 AM.