Dim oFileSys,oFolder,aFiles

Set oFileSys = CreateObject("Scripting.FileSystemObject")
Set oFolder = oFileSys.Getfolder(oFileSys.GetAbsolutePathName("."))
Set aFiles = oFolder.Files

For Each file in aFiles
    If Instr(file.name,"xyz") > 0 Then
        newName = Replace(file.name,"xyz_","")
        File.move(newName)
    End If
Next