All you have to do is go to the Update tab, then Update CPC option. It will let you select your offer, traffic source, etc and then you put in the actual CPC for the period you wish to update (I usually do this daily for the day before).
Since P202 clicks often differ from the clicks you actually paid for at the traffic source, I take the total amount spent at the traffic source and divide by the number of real clicks that P202 is showing, and that's the real CPC that you put into the update field.
I never update the links with new CPCs, there's no need to with this method.