Upgrade from Server 2008 STD to 2008 ENT

We bought a new server for a child site recently. Our old standard was 32GB boxes. Now it's 48GB. But our standard for OS was STD, not ENT and STD can't see all that 48GB of RAM. And of course, we didn't notice this until months down the road. And I should mention we're on 2008 R2, but I think this works for both 2008 and R2. Just use a DISM command to upgrade in 2 minutes from STD to ENT:

1. From an admin cmd prompt, enter: dism /online /Set-Edition:ServerEnterprise /ProductKey:489J6-VHDMP-X63PK-3K798-CPX3Y

2. Allow the reboot, it will reboot once more after that.

3. From an admin cmd prompt, enter:

slmgr -ckms
slmgr -ato

slmgr -ckms clears the KMS entry and slmgr -ato activates a new one. What's the Product Key I'm listing? A generic, publically posted one you can use before step -ckms nukes it.

Oh, and this will require 2 reboots. No new patches will be needed either.