1) Does anyone know how to remove the air con system. Will the gas likely blind/kill me if I open any of the connections. Is the gas/liquid harmful?
First, safe and legal advice.
The coolant is highly environmentally harmful, and it is illegal to vent to atmosphere. It is also very likely to cause instant skin freeze, cold burns or frostbite on contact, and could be deadly if inhaled. So you MUST go to a professional to do any work on it, inc decommissioning.
Answer two, the less legal answer, but cheaper.
The amount if actual coolant in the circuit is quite low when full, and after a few years a fair proportion will have leaked out, so find a bolt that hold an AC component joint shut. Carefully, using thick leather gloves, glasses and a big rag, undo the bolt and gradually release the gas. Then, when it's all out, dismantle as you wish.
Best compromise, go to an AC equipped garage and ask them to empty the system for you. You might find that a call to your local council will yield a free or near free service to avoid environmental contamination, as seen in fridges and freezers.