Deleting Rows and Columns Throughout All Worksheets

Hi,

I get a monthly set of data spread out through 5 sheets in a workbook. All the data on each sheet is categorized in the same way, that is, they are all in the same row and column throughout the sheets. I want to delete Rows 1, 2, and 3, and Columns A, B, and G, throughout all all of the sheets. I also want to Un-merge every cell within the workbook. I'm trying to record a macro, but it doesn't seem to replicate properly into a new data set. Any help would be greatly appreciated. Thanks!

Should be

Option Explicit

Sub Test()
    Dim SH As Worksheet
    Application.ScreenUpdating = False
        For Each SH In ThisWorkbook.Sheets
            SH.Rows("1:3").EntireRow.Delete
            SH.Columns("A:C").Delete
            SH.Cells.UnMerge
        Next
    Application.ScreenUpdating = True
End Sub

 'OR
Sub Test1()
    Dim SH As Worksheet
    Application.ScreenUpdating = False
        For Each SH In ThisWorkbook.Sheets
            With SH
              .Rows("1:3").EntireRow.Delete
              .Columns("A:C").Delete
              .Cells.UnMerge
            End With
        Next
    Application.ScreenUpdating = True
End Sub

I'm trying to delete columns A, B, and G, not C. Sorry for any confusion

Option Explicit

Sub Test1()
    Dim SH As Worksheet
    Application.ScreenUpdating = False
        For Each SH In ThisWorkbook.Sheets
            With SH
              .Rows("1:3").Delete
              Union(.Columns("A:B"), .Columns("G")).Delete
              .Cells.UnMerge
            End With
        Next
    Application.ScreenUpdating = True
End Sub