If your A/C isn't working cause your low on freon (is that how u spell freon, it looks funny) , then you have a leak and its not worth spending the money to refill, without finding the leak and fixing it. But, if you want to give it a shot you can usually find a refill kit at your local parts store and it will have directions on the can. Good luck.
1986 GT T-Top. Driving Project