It's easiest to install the package just from the ppm shell:

C:\> ppm
ppm> install PAR-587
[download]

assuming you have the uwinnipeg repository in your list of repositories. The link from this page that you're referring to: http://cpan.uwinnipeg.ca/dist/PAR-587, doesn't display any information on the package, but this is not because the package isn't there, but rather for reasons internal to how the dynamic content is generated from the database - I'll look at improving that.