Yes, you have to do both the apt-get (or aptitude) install AND the appending in /boot/config.txt.

Basically the apt-get stage downloads the new kernel and matching headers, then they are ready in /boot as alternatives to the ones in use at the moment. You might see errors in the apt installation referring to ‘unable to make hard links’ or something like that. I think maybe that’s why we have to edit /boot/config.txt ourselves?

It’s the entries in /boot/config.txt that allow a non-default kernel name. See here for a good guide to these.

You can edit it with a text editor if you like or just paste the command provided, either way you should get the new (i.e. older. rpi2-rpfv) kernel on reboot. Do a ‘uname -r’ on reboot to check.

If you’ve made a typo or somehow the right files aren’t in /boot then the raspberry pi will not boot. I pull the card and edit it on another computer in this case. Hope this helps!!

apt-get install linux-image-rpi2-rpfv
apt-get install linux-headers-rpi2-rpfv

Or do you also append the boot/.config? And does this return the latest module?

Thanks!