Yes the procudure is preety much the same. Infact some custom roms already has the custom kernel inside them.
Anyways if you want to flash a custom kernel, find one for your phone ( probably from xda-developers ). If you found a kernel, if its already in a flashable zip, just flash it via recovery.
Otherwise put your phone in fastboot mode using button combination or via adb by typing **adb reboot bootloader** and flash the kernel using this command **fastboot flash boot filename**

Note you need to have a unlocked bootloader for this to work and adb and fastboot working.