a lot of people just cut the copper lines inside the air conditioners and let the freon out. Which is illegal and can nab you a fin upwards of $10,000 if I'm not mistaken. You also need to be EPA certified to be "playing" with freon. Most of them are R-22 and the older ones are R-12. Luckily I'm an HVAC mechanic so I can recover the freon safely.