[ONE General] Hilmesh:
"As every guide is written with a Foreword so is this. Please try at your own risk. I am not responsible."

Next this is neither my guide nor my work. I went through all the threads as mentioned in the various links given below. All I did was follow procedure from whichever thread / post was related with my condition. Once I even got confused with too much information but then again as they if we don’t try we never know whether we would have failed or succeeded. 

So I was able to do this only due the works of other people. All the credit & Thanks goes to them. I have tried and remembered and mentioned all the names. In case I have missed anyone please forgive me and point me the name and I will thank them too.

My Step by step procedure to root the device without wipe for devices who have never tried rooting their Oneplus One and are currently on 33R using the method mentioned in this thread,

Download the Recovery flashable zips of the complete ROMz - XNPH25R, XNPH33R

Follow the ADB & Fastboot Installation Procedure listed HERE(Also if you can then do read the complete post as it is very informative for Noobs like me :))

Download the Oneplusone-bootunlocker.zip from HERE (Again if possible please read this complete thread too as it is also very informative)

Download the Supersu file from HERE

Download the custom recovery file from HERE

Copy both the Flashable zips, Bootunlocker, supersu files to your device

Switch off your device. And Then boot into STOCK RECOVERY by pressing the VOL DOWN & POWER key

Apply update – XNPH25R and then keep the power key pressed until the screen turns off. DO NOT REBOOT

Now boot to fastboot mode by holding the POWER button & VOL UP Key. Connect it to the PC and let it install all the drivers

Go to the SDK Installation in your PC, and within that go to the folder PLATFORM-TOOLS. Copy the “openrecovery-twrp-2.8.0.1-bacon.img” or latest file which you must have downloaded from the TWRP site

Within the directory Press the Shift Key and right click and you will get an option “Open command Prompt here” – Do it. Type in the command

Fastboot boot openrecovery-twrp-2.8.0.1-bacon.img

. Wait for 30 Seconds your device will enter into TWRP Custom recovery

Make a Nandroid backup (Optional)

Go to the install option within the recovery and select the Bootunlocker.zip. make sure the signature verification check box in unchecked. Apply the zip.

Now once again go into install option and select the XNPH33R zip and apply

I rebooted the device after Step 14 as I forgot to apply the supersu

Once again followed the same procedure to enter fastboot mode (Step 9) and loaded the custom recovery as mentioned in Step 11 and then applied the supersu zip as mentioned in Step 13. Again rebooted and device was successfully rooted with SuperSU

Next I wanted to flash Franco’s latest Kernel (franco.Kernel-nightly-r20.zip). Downloaded from HERE

Again put device in Fastboot mode (Step 9) and loaded Custom recovery (Step 11) and installed zip file using same procedure as Step 13

Wiped Cache & Dalvik Cache & Rebooted the device. No Issues. Franco Kernel was installed

Credits -	I would like to thank everyone for helping me out. Full Thanks & Credits to [MENTION=294690]ifg[/MENTION] (Guide for XNPH300), [MENTION=5381511]Mnt-XDA[/MENTION] (Bootunlocker.zip & a great thread about Reset Unlocker & Tamper Bit), [MENTION=4183928]MICa.fighter[/MENTION] (CM11S official & untouched image collection), [MENTION=3292224]franciscofranco[/MENTION] (Kernel for Oneplus One), Chromium (From Oneplus One Forum for a great guide on Everything Rooting for Oneplus One), [MENTION=631273]Chainfire[/MENTION] (SuperSU), [MENTION=1540557]ralphwiggum1[/MENTION] (for already trying it and clearing my doubts and giving me confidence to proceed)