HTC One max- Back to stock /unroot procedure To get OTA

I have HTC One max- international (unlocked)(s-on) with cyanogenmod 12
It's running badly wid regular restarting & Hanging, so I need to get back to stock version to Get OTA
Plz Help me wid every step from Locking boot- loader to selecting correct RUU and install it
Details of version is attached...
Please , I m craving to get help