To get the latest release go to https://cran.r-project.org/ and download the file for your operating system. Open the downloaded file and follow the on-screen installation steps. All the settings can be left on default unless you want to change a certain behaviour.
Once the installation is finished click the Finish button.
Now it asks if you want to copy your packages fro the older version of R to Newer version of R. Once you choose yes all the package are copied to the newer version of R.
After that you can choose if you still want to keep the old packages or delete.
You can even move your Rprofile.site from older version to keep all your customised settings.
You can check R Version using the console
version