install nodejs v6 lastest directly from https://nodejs.org/dist/ under /opt and link to /usr/bin with automatic architecture recognition.
NODE_MAJOR_VERSION default is v6 , change it by exporting variables
export NODE_MAJOR_VERSION="v8"
if you are not root user install in your $HOME environment
NODE_DIR default applikationdirectory is /opt
export NODE_DIR=$HOME
NODE_BIN default Binarypath is /usr/bin
export NODE_BIN=$HOME/bin