What kind of backup plan do I need for installing perl modules in production?

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http://serverfault.com – I manage an application that has been rode hard and put away wet over the years, but is still expected to continue to work. The server OS has been maintained, but the Perl instance has not because there isn't anybody assigned to the box that knows Perl. I need to install a new module for a request, but my management is concerned about how we can back out the changes if there's a problem. I've used CPAN to install it locally on my machine, but there were a ton of dependencies that also had to be installed. Unfortunately, I don't have a test server to start on, I have to go straight to pro (HowTos)