Short answer: You canít!
Numbers 24 ends with Balaam giving a fifth and final oracle. In this one, he explains that the Amalekites, though they are currently the most powerful nation, will fall to ruin. And the Kenites, who are well defended, will succumb to Asshur. But even Asshur and Eber will be destroyed when ships from Kittim come. After this final statement, Balaam returns home.
The point of this oracle is lost on me. Why would Balaam bother to tell this to Balak and the Moabites? They will soon fall to the rampaging Israelites, so I doubt they will care much about the fall of the Amalekites or Asshur invading the Kenites only to be wiped out by the Kittim navy. It would be like telling Mongolia, just before you nuke them into oblivion, that Canada is going to invade Paraguay. Maybe they could use this prophecy to win a few bar bets before being obliterated, who knows?
People have been claiming to make prophecies since prehistory, but the reality is, theyíre either deluded or charlatans. Nobody (authors of the bible included) has ever been able to demonstrate an ability to make accurate detailed predications about the future. But think what it would mean if it were possible! If we take the bible seriously, and Balaam was able to accurately predict the future, then God has already predetermined everything! You are, quite literally, a meat puppet created and controlled by God. And even though you canít make any moral choices or demonstrate individual free will, youíll still burn in Hell for all eternity if God didnít predetermine you to be a good person. You may find this a bit hard to swallow, unless youíre a Calvinist.