/Set-Edition: /ProductKey: /AcceptEula | /GetEula: Use the /Set-Edition option to change an offline Windows image to a higher ...

/Set-Edition: [/ProductKey:]  
  [/AcceptEula | /GetEula:] 

  Use the /Set-Edition option to change an offline Windows image to a 
  higher edition. 
  You can also use /Set-Edition to change an online Windows Server 
  operating system to a higher edition. 
  The /ProductKey and /AcceptEula arguments are required for an online 
  Windows Server operating system but cannot be used in any other scenario. 
  Use the /AcceptEula argument to agree to the license terms for the higher 
  edition. 
  Use the /GetEula: argument to choose a location to save the Eula, so 
  that you can review it. 

  Use the /Get-TargetEditions option to find the  to use with 
  the /Set-Edition option. 

    Examples: 
      DISM.exe /Image:C:\test\offline /Set-Edition:Professional 
      DISM.exe /online /Set-Edition:ServerDatacenter 
        /ProductKey:12345-67890-12345-67890-12345 
        /GetEula:C:\Users
ame\Desktop\Eula.rtf 
      DISM.exe /online /Set-Edition:ServerDatacenter 
        /ProductKey:12345-67890-12345-67890-12345 /AcceptEula