The entire itinerary must be 'revalidated', and remain valid. On an "Asia 1" redemption, you are allowed 2 stopovers in addition to the point of turnaround.
So presuming you have:
NRT-HNL (stop) - SFO (stop) - LAX (dest) - NRT
You could change this, subject to availability to:
NRT - HNL (open jaw) OGG - SFO (stop) - LAX (dest) - NRT
Should work. Assuming there's inventory on OGG-SFO, of course. Which there might not be.