How do I update my TeX distribution?
You should update your TeX distribution regularly, as you would for any other software package. An up-to-date distribution is the primary requirement for use of the cjs-rcs-article class.
The update mechanism varies by distribution and whether you want to upgrade the whole distribution or just update packages after installation.
TeX Live and MacTeX
TeX Live is the standard distribution of TeX produced by the TeX Users Group. The distribution runs on all modern computer architectures, including Linux, Windows and macOS. MacTeX is a specially crafted version of TeX Live for macOS with a simplified installation and a few additional goodies.
The model of TeX Live is simple: install everything.
TeX Live follows an annual release schedule. It’s a good idea to install the new release every year (note that the update usually occurs in March). This should allow you to continue using all TeX-related software—including the class—without any problems.
If a new version of the class is published during the year, you will need to update cjs-rcs-article. You can do this via the command line, a graphical interface (TeX Live Utility on macOS; TLShell TeX Live Manager on Windows) or the package manager of your operating system (on Linux).
MiKTeX
MiKTeX is the main alternative to TeX Live. Originally a Windows-centric distribution, it is now available on macOS and Linux.
By default, MiKTeX starts with a minimal system (“Just Enough TeX”), and its package manager installs missing components from the internet as they are needed. This may be inconvenient if you need a new component while offline.
In MiKTeX, all maintenance of the TeX distribution is done through the MiKTeX Console.