I would like a macro un unselect a library reference. I have the following
code to set a reference, but I am curious as to how I would use a macro to
un-set a library. Thanks!

This will set a reference to ADO:

Sub AddADO()

Dim r

For Each r In ThisWorkbook.VBProject.References
If r.GUID = "{00000205-0000-0010-8000-00AA006D2EA4}" And r.Major = 2
Then
Exit Sub
End If
Next

On Error GoTo NOTFOUND

'although usually the ADO version will be higher, doing Minor:=0 will
install
'the higher version if available. On the other hand when you specify
Minor:=5
'and only a lower version is available, this can't be installed
'----------------------------------------------------------------------------
ThisWorkbook.VBProject.References.AddFromGuid _
GUID:="{00000205-0000-0010-8000-00AA006D2EA4}", _
Major:=2, Minor:=0
Exit Sub

NOTFOUND:
On Error GoTo 0

End Sub