How to change the Domain “Short Name” in Windows 2003

I administer a Windows SBS 2003 server for a company called XYZ Associates. The following lists the AD Domain information for this server. Please note that I inherited this server and did not set it up.

Domain short name:         XYZASSOCIATES  
Domain DNS name:           XYZ.local  
Forest DNS name:           XYZ.local  
Site name:                 Default-First-Site-Name  
PDC role owner:            CN=NTDS Settings,CN=XYMAIN,CN=Servers, 

                           CN=Default-First-Site-Name,  
                           CN=Sites,CN=Configuration,DC=XYZ,DC=local
Schema role owner:         CN=NTDS Settings,CN=XYMAIN,CN=Servers, 

                           CN=Default-First-Site-Name,CN=Sites,  
                           CN=Configuration,DC=XYZ,DC=local
Domain is in native mode:  True  
Forest-wide Schema  
  Master FSMO:             CN=XYMAIN  
Forest-wide Domain  
  Naming Master FSMO:      CN=XYMAIN  
Domain's PDC Emulator FSMO:CN=XYMAIN  
Domain's RID Master FSMO:  CN=XYMAIN  
Current Userid:            CN=Scott McKinney,  
                           OU=SBSUsers,OU=Users,OU=MyBusiness,DC=XYZ,DC=local
Current domain controller: XYMAIN.XYZ.local

How can I change the Domain short name XYZASSOCIATES to just XYZ? It is a source of constant typos for me when doing any domain related work and the extra 10 characters don't add anything unique or necessary to the domain name.

I looked at all of the items and properties in Active Directory Domains & Trusts, Active Directory Sites & Services, Active Directory Users & Computers and can't find any reference to XYZASSOCIATES.

Are there any ramifications to existing users and joined computers if the short name is changed, or would they seamlessly update their credentials to use the new short name?

Thanks in advance for your help and insight.