Ideally you consult with your system administrator on how to upgrade your version of Perl.

Personally, I would recommend installing it under (for example) /opt/perl5.22/ so it doesn't conflict with the system perl or other installations.

If you have questions regarding the ActivePerl Enterprise Edition, I suggest that you consult with ActiveState directly. No other versions of Perl as provided by ActiveState seem to be available for Solaris.

In my experience, building a standard Perl for Solaris is fairly easy. Following the Installation From Source instructions should give you your own Perl installation that you can use in parallel to the existing version. Again, I recommend configuring it that the new Perl sits under /opt/perl-5.26 instead of overwriting /usr/bin/perl. Replacing the system Perl will bring far more problems than it solves usually.