Help to get Back to stock /unroot procedure To get OTA with each steps

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 or I can do it with downloaded Stock Backup & Recovery file. I am at nowhere at this
Please , I m craving to get help
Fastboot screen shows
Tampered**
Unlocked**
T6UL PVT SHIP S-ON RH
HBOOT- 2.49 . 0000