UPDATE 2021
nvm is working and easier than brew, try it!
I’ve to downgrade to Node 6 because Node 7 which has some bug that I’ve to avoid. It should be easy task but apparently it’s not, even with Homebrew (don’t ask me to use nvm it’s throw error on me so no joy!) and here’s my answer on stack overflow (after try all that but none of them work).
I’ll write it down here too just in case I need it.
Here’s step by step.
To see your current node version
$ node --version
To see available node versions
$ brew search node
To unlink from current version
$ brew unlink node
Install any version e.g. 6
$ brew install node@6
To link installed version
$ brew link node@6
To see your current node version (again)
$ node --version
This take me 30 minutes to figure this out so it’s worth blog it!
Bonus
To revert to current node version (7.5 ATM)
Gotcha
$ brew link --overwrite node
Linking /usr/local/Cellar/node/7.5.0...
Error: Could not symlink share/doc/node/gdbinit
Solution
$ sudo chown -R $USER /usr/local
$ brew link --overwrite node