Hi Rick,
Yes, unfortunately, all the bits of information is scattered. Have you looked on the Vim Wiki? Let us know what you find there if you look. Here is what I did:
1. From the Homebrew web site, install Homebrew using their shell command.
Then from Terminal, with "brew" installed, and in your own user account (not root)...
2. brew install macvim --override-system-vim
3. brew linkapps macvim
4. Add to your /home/username/.profile (or .bashrc) these definitions:
export EDITOR=mvim
export VISUAL="mvim -f"
export FCEDIT=mvim
I learned about the above from these two posts, the first one perhaps having the most information:
http://apple.stackexchange.com/questions/59375/how-do-i-install-macvim
https://github.com/Valloric/YouCompleteMe#mac-os-x-super-quick-installation
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