Uninstall csv import plugin

Hi there, newbie here!
I´m using the Omeka version 2.5 and tried to install the CSV import Plugin (Version 2.0.4 by Roy Rosenzweig Center for History and New Media). There´s a message “This is not a valid plugin.” and no uninstall ou desactivate option. Not possible to upgrade or install another version. Any suggestions, please…?

How did you get and install the plugin (zip download or git checkout)?
What is the path to your plugin.ini file? (should be /plugins/CsvImport/)

Problem solved! I get the plugin from Escher but it seems it’s not working well, so I downloaded a new version from the omeka page.
Thanks anyway!