how to flash my original 5.1.1 kernel ?

HI everybody
I updated my n910H to 5.1.1 , worked well and decided to flash a custom kernel . also faced to problem with wifi and now i decided to flash my original kernel.

i extracted the boot.img from update package N910HXXU1COH4_N910HOLB1COH4_N910HXXU1COH3_HOME.tar

now, im not sure how to flash it !! via odin or anything else needed

thank u for your help :)