Are you looking for a vba solution to this problem? You can identify the list level relatively easily along with a style name. Those two bits of information will allow you to restyle according to level.
Code:
Sub TestLevels()
Dim aPar As Paragraph, sNum As String
For Each aPar In ActiveDocument.Paragraphs
If aPar.Style = "List Paragraph" Then
Debug.Print aPar.Range.ListFormat.ListLevelNumber
If aPar.Range.ListFormat.ListLevelNumber > 1 Then
aPar.Style = "List " & aPar.Range.ListFormat.ListLevelNumber
Else
aPar.Style = "List"
End If
End If
Next
End Sub