ConTeXt Standalone/TeX Live
Show packages to be updated
tlmgr -location http://minimals.contextgarden.net/texlive/beta update --list
Update all packages
tlmgr -location http://minimals.contextgarden.net/texlive/beta update --all
Install only a single file
tlmgr -location http://minimals.contextgarden.net/texlive/beta update context-packagename
tlmgr install -reinstall packagename