Like most people I've content from 3 sources, official RF2 bought from Steam Store, content from the steam workshop and downloaded content installed from the Packages folder. When in game when in the "Manage Content" section. If I try and delete stuff installed from the packages folder, the uninstall option is greyed out. Even removing the file completely from the folder doesn't appear to remove the content. What am I doing wrong or is this a bug with the game?
You first need to uninstall the series MODs that are using the content. You can only uninstall content that is not in use by a series or server mod, otherwise it would break the mod.