Here is the blurb from United. Good luck, but, I think you are going to have to pay the change fee.
Revised travel policies and qualifying dates:
Customers with tickets issued on or before March 31, with travel dates on or before May 18, 2003, may postpone their travel to be completed by December 31, 2003 without penalty.
For customers who choose to postpone travel and reschedule for a future flight, the full value of the unused ticket will be applied toward the purchase of the new ticket with no re-ticketing fee. If the new fare is lower than the original fare and the original ticket was non-refundable, United will issue the customer a travel voucher for the difference. If the fare is higher, the customer will be required to pay the difference in fares.
To be eligible for this offer, originating travel must fall within the qualifying travel dates and to postpone travel, customers will need to contact United or their travel professional prior to their originally scheduled departure or April 19, 2003, whichever comes first. One change per ticket will be allowed under this waiver.
Conditions for the postponed/rebooked itinerary are mandated by the rules of the new fare.
For customers enroute, United will waive the change/cancellation fee one-time to allow flexibility for customers who want to change their travel plans. The rebooked travel must occur by May 18, 2003.
For more information on Uniteds change policy, customers are invited to visit the carriers website,
www.united.com or to call United Reservations at 1-800-UNITED-1. To rebook travel, customers should contact United Reservations or their travel professional