The following command will update all packages in every project to the latest version available from nuget.org.

Update-Package

You can also restrict this down to one project.

Update-Package -Project YourProjectName

If you want to reinstall the packages to the same versions as were previously installed then you can use the -reinstall argument with Update-Package command.

Update-Package -reinstall

You can also restrict this down to one project.

Update-Package -reinstall -Project YourProjectName

The -reinstall option will first uninstall and then install the package back again into a project.

Thanks to stackoverflow