Hello all. Been a long time. I am stuck. I have the HTC One with Hboot 1.56. Kit Kat came out and will not intergrade with my Pioneer head unit. Basic works, but no appradio. I talked to Pioneer and has to be Android 4.1.2 for appradio to work and the 4.1.2 firmware. So. I unlocked my One and rooted it on the hunt to find a way to roll back Androids Kit Kat and all I have is an unlocked phone. Its been years since I did any custom rom flashing and a lot has changed since. When I got the Sprint update to Kit Kat I didn't know the Pioneer head unit wouldn't work, something about the stereos firmware is not compatible with Kit Kat or its firmware and Pioneer is not sure they will have an update, or when. I guess Im stuck on stupid. I tried to get S-Off.. Nothing worked on Hboot 1.56. Read I have to change the Kernel or flash a custom rom, but I want to stay stock. Any easy way to just roll back using a RUU file? I did it before on the HTC Evo 3d and worked. Like I said, I must be stuck on stupid.. Thanks all.