(Re)move ~/.vim and ~/.vimrc if you have them already, and run:
git clone https://github.com/Casecommons/vim-config.git ~/.vim
cd ~/.vim
git submodule update --init --recursive
ln -s ~/.vim/vimrc ~/.vimrc
Provided your working copy is clean, updating is about the same as installing:
cd ~/.vim
git pull
git submodule update --init --recursive