How to recharge freon in car ac system?

I have ford freestar 2005,
Can someone tell me please how to charge freon if there's already some quantity inside the system? Thanks
The ac work I get little bit cold air (15c) but not enough.

How to get out of a used car (as is) contract?

My family bought a used car about 2 weeks ago (please note that we're not car experts and do not know what to look at or know if something is wrong). It had failed DEQ the first time and we took it back to the dealers who said they would fix the problem and run it through DEQ for us again. It had failed a second time. We asked for the CEL to be fixed because it would not turn on when doing the self test. However, they ignored our request and fixed the fuel cap light (replaced the gasket). Something seemed wrong, so we went to Ford (they have been very realizable for us) to have it checked. We found out that they had messed with the car greatly and it won't pass DEQ and other things without extreme payments. It is not worth keeping the car and we want a refund. How do we get out of the contract (as is/with an arbitrator)? Firstly, it is illegal to sell a car that won't pass DEQ. Secondly, they lied and manipulated us to get our money and the car out of their hands. And lastly, we don't have the money nor trust with the damage done to the vehicle. If any advice or recommendations, it would be appreciated.

How car braking system work?

I have a question about how does car/van stop while applying brake.
I have ford freestar which have 4 disc brake system.
It run only with two front wheel which are connected to transmission or engine.
So my question is when I apply the brake pedal, the brake are apply only on front 2 wheels or also on rear wheel?