Just use a walkthrough...
The walkthrough won't help him...but there is a
tactic that might.
Edit: Okay, he's said that he doesn't want to cheat, so here's one suggestion:
First, try and place two pieces so that they are next to one another in a horizontal row. Then try to make a diagonal row of two pieces, but place the rows so that they will be crossing at their respective third pieces, like this:
Now try and place a piece in the fifth spot, if you will, of each row:
Then place the piece that is 'shared' by both rows. As you can see, the computer will only be able to block one of your rows:
That's pretty much it. Of course, you may have to block the computer at times, and this tactic won't work each and every time you try it, but I think it gives the player one hell of an advantage. Plus it's not cheating.