Can it get to the internet for updates?

If yes, then you can adjust your /etc/apt/sources.list have internet "deb" lines.

deb http://http.us.debian.org/debian stable main contrib non-free
deb http://security.debian.org stable/updates main contrib non-free

Then do:

apt-get update
apt-get upgrade

You should only need to "upgrade" as you are going from lenny(test) to lenny(stable). But an "upgrade" will not ever remove packages, there fore some upgrades might not be allowed and show as "on hold" or "held", you might need to do a "dist-upgrade" and be picky about what you do and don't allow. You can piece meal the held ones and the deps required will show up for you... allowing you to piece it.

Hopefully, the APIs/ABIs didn't change much from from when you installed the Lenny Testing version, and you shouldn't get a lot of issues. Lenny was, after all, one of the better transitions from "testing to stable" and "oldstable to stable"



Now if you can't do the internet updates, its "download all the DVDs or CDs" and register/scan them all with apt and upgrade from there. You have to use "apt-cdrom" for that. man apt-cdrom will tell you everything you need to know.

With the cdrom method, I'd do the same "upgrade" only and "dist-upgrade" only if needed or piece-meal it.