Sub ChangeParasAfterHeading()
    Dim para As Paragraph, nextPara As Paragraph, oRng As Range
    If Selection.Type = wdSelectionIP Then
 MsgBox Prompt:="You have not selected any text!"
 Exit Sub
End If
    Set oRng = Selection.Range
    With oRng
    For Each para In oRng.Paragraphs
        If para.Style = "Heading 1" Then
            Set nextPara = para.Next
            If Not nextPara Is Nothing Then
                nextPara.Style = "Body1"
    Else
    If para.Style = "Heading 2" Then
            Set nextPara = para.Next
            If Not nextPara Is Nothing Then
                nextPara.Style = "Body2"
                Else
            End If
        End If
        End If
        End If
    Next
End With
End Sub