Unroot guidelines needed for E8 m8sx with s-on

I messed up on the rooting, wiped OS & had to downgrade to kitkat. The phone's still S-On. Now I want to unroot the phone to receive OTA update. I am supposed to flash the stock rom and stock recovery, but I couldn't find any from http://ift.tt/1BPwbEL this thread. And I have never tinkered with htc devices so I am basically a noob at this point.

So, a step by step suggestion from a good Samaritan will really be helpful. TIA. :)

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