Yes, its pretty easy. The international phone agents made the adjustment but they require you to contact the Customer Service Center (during their open hours) to manually adjust the mileage so it doesn't require the newer limits. Presummably at this point they note your record of this one-time change. The original phone agent was able to put the itinerary changes on hold until the customer service center opened the next morning. I had to call back in to Customer Service to request the adjustment. I saved my one change to add my "free Alaska one-way" prior to my EK segments as well as an EK award change date. (ANC-SEA-DFW; DFW-DXB-EBB all in First with a 5 month stop at DFW).