1. Set the WCSTOOLS environment variable pointing to the location of
   your WCSTools distribution:

   $ export WCSTOOLS=/path/to/wcstools # Bourne shell and friends
   % setenv WCSTOOLS /path/to/wcstools # C shell variants

2. perl Makefile.PL

3. make

4. make test

5. make install

If compilation fails, please make sure the version of WCSTools you're using
matches that listed in README as a requirement for this version of the
module.