How to Change AS server channel to ES channel

[hike]

Our Situation:
  Old manager: buy RHEL AS & pay yearly subscription fee.
  Manager change.
  Cheap New manager: move AS servers to ES.  (Costs less; more budget for
windows.)

Is it possible to change our RHEL 4 AS servers from the AS channel to the
RHEL 4 ES channel?

This is not an option shown in our account and I suggested that the manager,
being the guy with the money, contact Red Hat about this.
Being a true cheapy, he dumped the assignment to a new jr. administrator.

If it is possible?  Ifso, how?


TIA,

hike