You can't change them.. the best you could do is to recreate the ad w/ the tracking url included.
That sucks as I have the ads already successfully running (profitable as well) adn would hate to mess with them. On the other hand its my stupidity for not putting the tracking URL's in in the first place.
yap ive done that before....just recreate the same ad, and watch it to see if gets same .ctr ..and once it does...pause the other ad.
I always use urls that go through my own redirecting site. It gives me the freedom to change links whenever I want.