User blog:Civic42/How do I make someone last hit?

There is one friend I like to play with and that he is HORRIBLE at playing. He knows how to build Heimerdinger but he always pack Philostone and Kage's Lucky Pick because he says that he can't earn enough gold. I was like because you are pushing too hard and doing it wrong with your rockets. I go do a custom game with him and another friend who is just there is screw around as Ahri. I WAS MORE AFRAID of Ahri than of Heimerdinger. I was playing passively with Cass to teach him and sort of make him learn how to last hit. NOPE, he drops turret and spams rockets and nade till he is out of mana. I told him NEVER EVER to be caught w/o mana(told him that for ages). He doesn't listen and psh me all the way to my tower in mid. OK, fine, lets play beat down. I just kept farming at my tower. I am more or less free farming because he would consistantly bash my minions. Ok, fine, I'll deal with that.I use some mana to push the lane back up. I told him that this is about learning to last hit not pushing. He didn't listen and kept pushing. I warned him that if I had another person or a jungler you would have been dead from OVER EXTENDING. He didn't listen and kept at it. I let him off easy by pummeling him almost into the ground. He packed flash/heal. I go up to him (Q,e,e,e,e,W,e,e,e,e,e,e,e,q,e,e,e,e,e) dead. He flashed out and I didn't chase. He was like that was close. I was like -_-. I let you live. Ahri ganks and I die. This pretty much repeats for several more times where i passively let him try to last hit and all he does is spam and push. Most of the time I let him off easy by waiting out flash/heal's cooldown. CS total when I surrendered Cass 288 Heim a little over 150 Ahri a little below 150.

I have the replay(I think) I would like to not upload it but if you guys really want to see it I can.

TL;DR: I MAD AND How do I teach someone to last hit.