Yes the procedure is pretty 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 adbADB by typing adb reboot bootloader
and flash the kernel using this command fastboot flash boot filename
Note you need to have aan unlocked bootloader for this to work and adb
and fastboot
working.