It will cost a few $, but you can do it...
If you go to the carrier who issued your e-ticket and ask them to print you flight coupons instead (and probably pay their $10 fee), you can then walk the flight coupons over to whichever airline will agree to accept them. DL is generally very good about online transferring YCA fares, but they usually turn into LDG or UDG fares on DL...