just follow the instructions on their github
just make sure to install build essensials
sudo apt-get install build-essential rbp-userland-dev-osmc pkg-config
dont forget
./configure --prefix=/usr --disable-gui --with-boost-libdir=/usr/lib/arm-linux-gnueabihf/
so you dont get a gui
ps if you fail at your own, i could make a howto for it since there doesnt seem to be one on the howto section but please try on your own first.