The sbm12 post above seemed very CO-centric (e.g., keeping the record open, paying a change fee, etc.). CO operates a bit differently than most carriers, and this sounds like a UA reservation/UA ticket, and the mechanics work a bit differently between the two carriers.

For UA, assuming your ticket starts in HNL, really you just cancel the reservation, which will leave you a credit of the ticket value. Since this is UA, hang onto the ticket number. No need to keep anything pending. The reservation number can die, since it's independent of the ticket number (the ticket is what holds value).

The unused ticket can can then get applied to any new reservation that person wishes to make (less the change fee) within a year from date of original ticket issue. On UA (like on most carriers), you don't pay a change fee, rather your change fee is deducted from the old ticket's value. So if it's a $600 ticket, with a $150 change fee, and your new ticket is $450, you pay nothing.