How can I install Icon pack (theme)?

[rovf]

The Editra plugin page gives the following advice for installing a theme:

"The themes downloaded here can be installed by dragging and dropping the downloaded egg file on to the Install page of the Plugin Manager."

This doesn't work. First, the files to be downloaded, are zip files, not egg files (for instance Crystal-0.2py2.7.zip). Second, unpacking them does not reveal an "egg file", but two directories, one being called EGG-INFO.

When I drag and drop the zip file to the install page of the Plugin Manager, this is not accepted. An egg file does not exist. So, how can I install the Icon packs?