I had to change award tickets this year. Both inter-island and flights back to west coast.

Because I booked the 3 inter-island flights together on the same reservation, they only charged me a $30 transaction fee to redeposit for all 3 award tickets...

Because I booked the 3 one way flights back on the same reservation, they only charged me $150 to redeposit the miles.

It was cheaper to redeposit the miles than to pay change fees....

It was not immediate return of the miles to my account if I remember correctly, but I got them back within a few days...

So just make sure you book your award tickets together on the same reservation. If you do it on different reservations it will be per person..