[Q] How debranded HTC One from Voodafone UK topic

Hi Guys
I have my Gold HTC One from Voodafone UK and this phone is branded to this network, now I want ask you guys that is possible Debranded this phone and flash stock rom? If I do this after ppdate via OTA will be work? What steps I spouse to doing first?

I lookong this all answer for my question on this forum and I can't find clear information about this how debranded this phone.
Please give me some tips.

I know that first step this is unlock bootloader and after ....? What flashing custom ? or maybe S-Off? or maybe first doing nandroid backup? or chage CID ?

I don't know with step spouse to be second and next and next.

Thanks for any advice.

P.S First and main question is : This is Possible debranded to Factory roma and get OTA Update after?