servicing an AC that isn't working?

If you have never worked with automotive ac you are best off bringing it to a qualified shop. If you would like to try and diagnose the issue you will need to start with a set of ac gauges and check pressure on the high and low side. This isn't anything that can be explained quickly here however. Here is a link to find a shop near you. https://www.youtube.com/watch?v=PRSoRkM8GcM Alex