VBA Code: Recursive File Rename?

Hello all,

I'm trying to adapt the below file rename code in order to be able to operate recursively (i.e. perform the operation on all files also found within subfolders of the chosen folder), preferably using File System Object, but I'm having trouble figuring out how to do so.

Sub RenameFiles()
Dim xDir As String
Dim xFile As String
Dim xRow As Long
With Application.FileDialog(msoFileDialogFolderPicker)
    .AllowMultiSelect = False
If .Show = -1 Then
    xDir = .SelectedItems(1)
    xFile = Dir(xDir & Application.PathSeparator & "*")
    Do Until xFile = ""
        xRow = 0
        On Error Resume Next
        xRow = Application.Match(xFile, Range("A:A"), 0)
        If xRow > 0 Then
            Name xDir & Application.PathSeparator & xFile As _
            xDir & Application.PathSeparator & Cells(xRow, "B").Value
        End If
        xFile = Dir
    Loop
End If
End With
End Sub

Can anyone provide any guidance? Thank you in advance for any and all help!