This can be done using a simple iteration over the paragraphs contained in the document:
Sub CleanupHeadings()
Dim p As Paragraph
Dim pNext As Paragraph
For Each p In ActiveDocument.Paragraphs
If IsHeading(p) Then
' check the following paragraph
Set pNext = p.Next
If Not pNext Is Nothing Then
If IsHeading(pNext) Then
' next paragraph is a heading too, so delete current paragraph
p.Range.Delete
End If
Else
' no following paragraph, i.e. document ends with a heading
p.Range.Delete
End If
End If
Next
End Sub
Function IsHeading(para As Paragraph) As Boolean
IsHeading = para.OutlineLevel < wdOutlineLevelBodyText
End Function