changing Serial number of a Primary Server

We just did an upgrade of a primary from w2k3 to W2k8 according to various Novell document. New server was created.
1. Using Zman commend, backup files.
2. Stop the current server and services as well removed from the network.
3. changed the name in the DNS and Ip address to be the same as the old server,
4. Install Zenworks to the same level (11.2.3a)
5 restore the backup from step 1.
6. The server up and running, but the serial number in the Summary page of the server is different to what it shown in the inventory page.

We left the old server device in the zone from the start, as there was nothing mention in the document about removing it. So when we brought up the new replacement server, it shown in the ZCC as 2 devices with the same name. From the summary pages, we were able to figure out the orphan device and removed it from the zone. We notice the serial number from the summary page is not the same as what's in the inventory page. The serial number from the inventory page is what we gather is the correct number.

Help: how can we change the serial number off the summary page of the device to be what it is shown in the inventory?
Thanks