How to remove an inactive version of packages installed with easy_install

I found out that I have two versions pipinstalled on my OS X, and I would like to remove the older version (which is also marked as "inactive" on yolk -l).

In another post, https://stackoverflow.com/a/312616/2709 / ... I found that you can remove a package using the command pip uninstall. But in my case, I would like to remove only the old version of the package, leaving the active version untouched. How do I do this properly?