To remove all node.js installations, the best way is to manually delete those files from locations it resides.
Depending on versions of LINUX, the following folder locations should be examined and removed:
/usr/bin/node /usr/bin/npm /usr/local/bin/npm /usr/local/share/man/man1/node /usr/local/lib/[dtrace]/node.d ~/.npm ~/.node-gyp /opt/local/bin/node opt/local/include/node /opt/local /lib/node_modules
Issue command rm -r [folder name] or rm -rf [folder name] to remove the folders. The latter just goes to delete without prompting for permissions.