[Q] How to again unroot/Lock HTC One M7 which is still on stock/factory ROM. topic

Hi Guru's

I have rooted my HTC One M7 (India, CID - HTC_038) but didn't flash it with any custom ROM and continued using the stock/factory ROM. Now, I want to revert to the locked/unroot mode since I don't want to miss the OTA updates from HTC. I see that there is some information available on XDA and other forums but it looked fragmented to me. Can you please guide me or re-direct me to correct source which has more clear details. Please find the details. Thanks in advance !
Note: I am using TWRP.

Details -
M7_U PVT SHIP S-ON RH
HBOOT - 1.570000
RADIO - 4T.28.3218.04
Android version - 4.4.3
HTC Sense - 6.0
Software Number - 6.13.707.106
HTC SDK API Level - 6.25