I updated from an alpha 4 base install as follows. It is worth noting that, when removing connman/network-osmc packages prior to updating, you shouldn’t be working over ssh.
Change /etc/apt/sources.list to work with Debian rather than Raspbian:
deb http://ftp.debian.org/debian jessie main contrib non-free
deb http://ftp.debian.org/debian/ jessie-updates main contrib non-free
deb http://security.debian.org/ jessie/updates main contrib non-free
deb http://apt.osmc.tv jessie main
Then do:
sudo apt-get update && sudo apt-get install debian-archive-keyring
From looking at my dpkg selections, you’ll need to remove the following packages. Some would be removed as deps, but I can’t remember which.
sudo apt-get remove rbp-eventlircd-osmc rbp-libafpclient-osmc rbp-libcec-osmc rbp-libnfs-osmc rbp-librtmp-osmc rbp-libshairplay-osmc rbp-lirc-osmc rbp-mediacenter-osmc rbp-remote-osmc rbp-splash-osmc connman network-osmc liblircclient0 lirc ftr-osmc
I put a few packages on hold to stop them installing:
sudo echo 'amv61-network-osmc hold' | sudo dpkg --set-selections
sudo echo 'amv61-connman-osmc hold' | sudo dpkg --set-selections
sudo echo 'ftr-osmc hold' | sudo dpkg --set-selections
Now you can do an apt-get upgrade to pull in all the standard Debian armhf packages. Next, install the rbp2-* packages.
sudo apt-get install rbp2-device-osmc
As I remember, this will pull in everything required, i.e. the new kernel, kodi etc.
The only remaining thing, as far as I’m aware, is to make the device boot the updated kernel, but I’m not so familiar with the Pi… Will simply copying /boot/vmlinuz-3.18.7-3-osmc to /boot/kernel7.img do the trick?