ssh to the atv2 then run the following commands…
wget http://mirrors.xbmc.org/apt/atv2/deb/org.xbmc.xbmc-atv2_10.0-7_iphoneos-arm.deb
dpkg -i org.xbmc.xbmc-atv2_10.0-7_iphoneos-arm.deb
rm org.xbmc.xbmc-atv2_10.0-7_iphoneos-arm.deb
NOTE:
the full list of debs can be found here:-
http://mirrors.xbmc.org/apt/atv2/deb