Partner Reward - Cancellation?
 

I have a CX partner award in economy booked for next year.

Due to a load of miles that have posted last week I am now looking to fly J instead of Y.

Does anyone know what the best way is to do this? If I cancell then rebook, will I lose the taxes that I paid?

Does anyone have any experience of CX rewards? There seems to be multiple Y seats but only 2 J on most flights. Thanks