Buy a kit at Wal-Mart or auto parts comes with instructions You shouldn't...freon in your car is under high pressure and takes special equipment to do properly. In addition, today's cars require a very specific quantity of freon to work properly. Too much will result in high internal pressures and heat, too little will prevent proper lubrication...both of these conditions will lead to an early death of the compressor and a very expensive repair. There is an organization where you can get more info, and I have help in locating good mechanics on my site. See the related links for more info. Hope this helps!
We would need to know the engine model, or at least the engine displacement, in order to answer this. That's much more relevant to answering the question than the number of gear ratios in the transmission.