delete from text files

Hello. Try this code

Sub Test()
    Dim x           As Variant
    Dim sFolder     As String
    Dim sFile       As String
    Dim sTxt        As String
    Dim nStr        As String
    Dim f           As Integer

    With Application.FileDialog(msoFileDialogFolderPicker)
        If .Show Then sFolder = .SelectedItems(1) & "\" Else Exit Sub
    End With

    sFile = Dir(sFolder & "*.txt")

    Do While sFile <> ""
        f = FreeFile
        Open sFolder & sFile For Input As #f
        sTxt = Input(LOF(f), f)
        Close #f

        x = Split(sTxt, vbCrLf)
        nStr = "," & Split(x(0), ",")(UBound(Split(x(0), ",")))
        x(0) = Replace(x(0), nStr, "")
        sTxt = Join(x, vbCrLf)

        f = FreeFile
        Open sFolder & sFile For Output As #f
        Print #f, sTxt
        Close #f
        
        sFile = Dir
    Loop
End Sub