Once you remove the rings from the pistons you don't reuse them (at least I wouldn't in a race engine). Really easy to damage them taking them off.
No more likely to damage them taking them off than you are putting them on; though I did not suggest taking them off the pistons. As to reusing them; how does a ring know it has been removed from a cylinder?
August "Car Craft" has some enlightening reading if you haven't already.
