How to install new kernel on eMMC without boot button

Hi, I am newbie.
I am just curious about that how to install new kernel on eMMC without boot button.
I have to make sure Installing kernel step, I get answer before.
following the website tells me
http://www.eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-InstallKernelandRootFileSystem

  1. Copy Root File System
  2. Copy Kernel Files

according reference manual
and then holding the boot button and insert SD card.

Is that right ??

if that steps were right.
when I make a some product(ex. quad copter) as goods by beaglebone black.
the consumer has to be comfortable to upgrade OS, driver, kernel, etc…
so I need to know installing kernel without boot button.

does anybody know??