is it possible/difficult to upgrade from RHEL WS to RHEL AS

Hi all,

We bought an academic RHEL AS subscription for myhost1, but didn't buy
media, because we already had media for myhost2 running RHEL with a
subscription through Dell.  We installed RHEL on myhost1 -- not
realizing it was Red Hat Enterprise Linux WS release 3 (Taroon) and our
subscription was for AS.  So, when I tried to add the system and assign
the channel, I got "This assignment would exceed your allowed
subscriptions."

Is there an easy way to upgrade?  If not, how hard is it to install AS
without CDs (Dell Precision 340)?  We really only need WS, but there is
no academic WS RHEL.

Donna