Remote Desktop Service (RDS)

Rename User Profile Disk (VHDX)

Logoff User from server

logoff <username/id> 

Close SMB-Sessions

With GUI

With PowerShell

Get-SmbOpenFile | ? {$_.Path -match "<SID>"} | Close-SmbOpenFile

-> After the above steps you are able to rename the User Profile Disk (VHDX)