Question about reward tokens

[Zombie]

Can I pay reward tokens to swap an items ability for a like ability?

I have an amulet with DR 10 Magic/Acid/Negative that also casts a few spells on charges (spells tied to the energy types). I would like to change the Magic DR for a different energy. I dont care at all about the spells, so if changing the energy changes or removes the spell thats fine with me. I think from memory its a necklass of the dracolich

To pay for the item from scratch is 15 tokens, and I just don't have them (I have 2) and I wouldnt be able to have the spells in it (even though I never intend to ever use any of them any way).

I also have a ring of dwarves that im keen to change both its energe resistances. I think that is a bit of i different situation though.

I can see how the question raises a few issues that would need consideration