Originally Posted by
guv1976
You should be able to cancel and refund the return portion of the roundtrip award after you have flown the outbound, but you might have to wait a few days for the outbound portion of the award to "fall off" the award record. At least, that's what I was told when I was (ultimately) able to cancel the return portion of a roundtrip award.
+1 I haven't tried it, but did look into this exact issue a few months ago and was told this is the only way it can be done to avoid the full r/t reprice.