To upgrade your Ubuntu From Edgy to Feisty (still beta) release Feisty Fawn, you just need to run two commands.

Do this at your own risk as for this moment, Feisty is still in beta release.

sudo aptitude update && sudo aptitude upgrade

to update and upgrade to the latest Edgy packages.

gksudo "update-manager -c -d"

With the -c it looks for new versions, and the -d tells Ubuntu to look for pre-released versions.

If you do not have graphics access to your machine, will have to use the second method.

which is this:

sudo vi /etc/apt/sources.list

and change all where you see edgy for feisty

next:

sudo aptitude update
sudo aptitude dist-upgrade