Yup, super simple! Locate the plugin in the Control Panel or More > Plugins in the sidebar, click on the title to open it as a tiddler, and then delete it. If you haven’t customized your tiddler toolbar, the delete button may be hiding under the “More actions” button/dropdown at the top of the tiddler.
This won’t remove any “real” tiddlers you’ve promoted from shadows (by editing them), so you may (or may not) want to go through the contents tab of the plugin and delete any non-bolded tiddlers first.