galaxy s3 update

[Android Question]

I have the galaxy s3 on the att network and I HATE the new update does anyone know how I can undue the update? I have tried to do a factory reset and it didnt work. I dont know anything about custom ROMs or how to root my device or any of that so if this is the best route can someone give me step by step directions? thanks email me at icedragon43701@gmail.com