Yes, Install TWRP in fastboot mode via "fastboot flash recovery (recovery file name).img"
then unzip downloaded backup folder (2014-04-18--09-26-29 KOT49H release-keys) and place it in SD Card/twrp/FA3APWG02523.
Then reboot to bootloader and enter into recovery from there. restore stock back from TWRP from here
Now boot up your phone and see if everything is working fine in your phone and you are able to use your phone such as calls/sms etc etc
If phone is working fine then again boot into bootloader and flash stock recovery via "fastboot flash recovery recovery_t6ul-2.61.401.3.img"
After this you need to enter into recovery from bootloader but this time method would be little different to enter into recovery unlike you used to go into TWRP/CWM Recovery. Once you hit power button in bootloader to enter into recovery then wait for the "htc logo" screen to go away. once its gone then press Volume Up button and power button simultaneous 4 or 5 times. You might see an error 5 times but ignore that and keep pressing Volume up button unless you see a Blue Stock Recovery Menu. if you see it then you have done it right. Here you need to wipe cache and do a factory reset and reboot system.
Now once you are done with above all, reboot into bootloader/fastboot mode and lock your bootloader via "fastboot oem lock"
Now you are on Stock Firmware and ready to take an OTA (if available) for your phone if everything goes right.
I hope now it clears everything and you would be able to do it easily
Important: If this works, then hit "Thanks" button in every post that I have replied you. LOLZZZ
first person in here that gave me so detailed instructions..... U ARE VERY GOOD PERSON! THANK YOU! i will let u know how it goes when i do it...