How to restore my HTC one m9 too stock?

[AC Question]

Hi, I want to un-root and basically go back to stock so I can update my phone and just have it completely stock and updated again. I have my phone rooted with like supersu and twrp recovery. I have s-on, I really just want to fix it, I kinda went into rooting without much knowledge, but I don't want to deal with it anymore. Most tutorials are hard to comprehend.