You need to install your own perl and leave the system perl alone. You might screw up your OS by messing with the system perl. If you have root permissions on the computer you're using, you can just download the latest version of perl and follow the installation instructions.
If you don't have root permissions, you can download perlbrew and use it to install perl in your local directories. You may just want to do that anyway because perlbrew makes it easy to manage multiple versions of perl in case you decide to try different versions of perl or you want to install perl both with thread support and without, etc.