nvm works great for switching between versions of io.js and node. Get it here:
https://github.com/creationix/nvm
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm
[ -r $NVM_DIR/bash_completion ] && . $NVM_DIR/bash_completion
export NVM_SYMLINK_CURRENT=true