The script will delete user accounts from the Admin group on a system. 
It will not delete any account that begins with "cls". This script can run on WinXP and Win7
the script inclue chain of server too, you can make a array of all servers you have and pass array so that
at a same time you can perform operation on all servers in array

I try to give an answer to the script requested on forum : https://gallery.technet.microsoft.com/scriptcenter/site/requests/Delete-AD-User-accounts-from-Local-Administrators-group-87803c48
PowerShell
Edit|Remove
#call the function as del-LocalAdmin computer1 c:\temp\admin.txt  
function del-LocalAdmin ($computerName,$adminContent) {  
$mycomputer=$computerName  
$Computer = [ADSI]("WinNT://$mycomputer,computer")  
$Group = $Computer.PSBase.Children.Find("Administrators") -notlike "cls*"  
  
    ForEach ($User in (Get-Content $adminContent))  
    {     
        $Group.Remove("WinNT://$User")  
    }  
  
}  
  
#or for more computers then use array of computers in using below code  
#$allmyservers = “com1”,”com2”   
#$Group = $allmyservers.PSBase.Children.Find("Administrators") -notlike "cls*"   
#ForEach-Object ($User in (Get-Content "c:\Temp\admin.txt")) {     
#$Group.Remove("WinNT://$User")  
#}