If you're going to manually patch a distribution, you forego most of the automation that CPAN provides you and have to do the steps manually:

1. Download and unpack the distribution. If in a hurry, you can let CPAN do that for you:

   cpanm --look Devel::CallParser
   [download]

   or

   cpan
   CPAN> look Devel::CallParser
   </li>
   <li>Patch the distribution:
   <c>
   patch < rt110623.patch
   [download]

2. Test the distribution:

   perl Makefile.PL
   make
   make test
   [download]

3. Install the distribution:

   make install
   [download]

4. Keep a backup of the current directory, for the next installation

Update: Corrected invocations of tools, as spotted by ibm1620