Flying MSY-IAH-HNL this weekend. Plans changed and don't plan to use the MSY-IAH segment (will be in Houston during the weekend). But need to take the IAH-HNL segment. Is CO going to cancel my reservation if I don't use the MSY-IAH segment? Any idea on how to avoid the cancellation?

Tried to change it at CO.com but it's repricing the whole itinerary, and the total difference + change fee is over $900 (paid half of that price for the roundtrip). Any idea on how to avoid the change fee?

Thanks!