Diplomacy is still very much a work in progress, so at the moment there's simply no way to edit the attitudes. A system will be added, but it might not be done before the AI is developed, so it could be a long time before there's a way to set or edit the attitudes.
Sorry about this GeorgiaBoy, but you're just going to have to wait with the rest of us for this particular game feature.
_________________"Anyone without a sense of humour is truly at the mercy of the rest of us."