Need help with an appeal letter to get ins to cover tt with hernia repair

Hi, I am going to have a hernia repaired and am going to fight insurance to cover a tummy tuck. I don't have rashes, but I do have the constant backache from the hanging skin. Can anyone offer me some advice or sample appeal letters? I have been on the site looking but I really haven't been able to find much. Has anyone ever had BCBS Health Options pay for one? Thanks for your help! Nicki