Well you need to complete the pro course with the school first. This is a long and painful process as Ariben is probably the most messed up organization you'll ever deal with. If you get your ratings then you can go to the owner, Mike Cohen and ask him for a job. He'll probably give you one if you've not pissed him off... as he runs on a short fuse this is easier said than done though. He'll ask you a few crackpot questions and if he's happy you'll be given some students. Any future CFI'ing depends on your ability to instruct, your ability to brown nose Mike and the availbility of students to teach. Right now the latter will be most limiting. Outsiders are rarely hired and are treated even worse than regular pro course grads.
Good luck, you'll need it, but if I can get a job there.......and I had a $5000 reward on my head for some of my earlier posts. Hope this helps.