The best way to deal with different versions of node is to install the Node Version Manager (nvm) using Homebrew.
You just need to write the following command in your terminal:
brew update
brew install nvm
mkdir ~/.nvm
nano ~/.bash_profile
and make sure that you add this to your .bash_profile:
export NVM_DIR=~/.nvm
source $(brew --prefix nvm)/nvm.sh
Now you can just use the command nvm from your terminal to simply install and manage new versions of Node in your computer.