1. Upgrade from Home to Pro - Changepk.exe /ProductKey VK7JG-NPHTM-C97JM-9MPGT-3V66T
2. Upgrade from Pro to Enterprise - Changepk.exe /ProductKey NPPR9-FWDCX-D2C8J-H872K-2YT43
3. Make sure they have an Microsoft E5 license in 365
4. Go to Activation and click Troubleshoot