Search for files in folders and subfolders

I cant seem to figure how to make the code below search thru subfolders, it will search the "strPath" only (original code by Jim Cone).
Any hints, tips or examples are appreciated.

'Opens each .xls file in the folder, makes changes and closes the workbook.
'Protected worksheets throw an error.
'Jim Cone - Portland, Oregon USA
'Modified RS 04.15.14, (Thank you Jim Cone)

Sub RemoveFooter()
    Dim objFSO As Object
    Dim objFolder As Object
    Dim objFile As Object
    Dim strPath As String
    Dim strName As String
    Dim WS As Worksheet

    Application.ScreenUpdating = False
    'Specify the folder...
    strPath = "C:\Users\rick\Downloads"

    'Use Microsoft Scripting runtime.
    Set objFSO = CreateObject("Scripting.FileSystemObject")
    Set objFolder = objFSO.GetFolder(strPath)

    'Check type of file in the folder and open file.
    For Each objFile In objFolder.Files
        If objFile.Name Like "*.xls" Then
            strName = objFile.Name
            Workbooks.Open objFile

            'Open Workbook
            'Clear Footer
            For Each WS In Worksheets
                WS.PageSetup.LeftFooter = ""
                WS.PageSetup.CenterFooter = ""
                WS.PageSetup.RightFooter = ""
            Next WS
            Workbooks(strName).Close savechanges:=True
        End If
    Next    'objFile

    'Cleanup
    Application.ScreenUpdating = True
    Set objFSO = Nothing
    Set objFolder = Nothing
    Set objFile = Nothing
End Sub

LJMetzer, your link was very helpful!
Thanks!