Is there a red line (like from a marker) near one of the leads? If so, that's the positive lead.
Failing that, at least make certain they're wired the same. That way you' ve got a 50% chance of getting it right. If you're certain they're the same polarity, hook them up and listen for a while. Then switch the leads to both tweeters and listen some more. If one way sounds better than the other, stay with that way,