[Q] help me please topic

Hi there
Do not bother
My htc one dual sim, am I install custom ROM
I did not backup the original ROM
Please create a backup of the original ROM 4.21.402.5 for me to leave
I want to go back to the original Android 4.4.2 back
please help me
i need to back original android 4.4.2 and them install android 5.0.2
Special thanks

xda-developers