Actually, EditorMonkey has included an uninstall script for quite some time now, and this is mentioned on the website and in the readme file…
This plugin MAKES ONLY 2 CHANGES:
– it turns off using the built-in wysiwyg editor by default for all users (global/admin setting)
– it turns off the per-user built-in wysiwyg editor…
And that’s it. All the other “changes” are restricted to editormonkey.
EditorMonkey uses a different version of TinyMCE than WP does, and so it keeps a separate copy.
To uninstall:
1) Deactivate plugin.
2) Reset “Use rich editor by default” from the Options > Writing page.
3) Reset “Use rich editor” in the User Profile page.
4) *OPTIONAL* Go into the database and delete all fields that begin with em_ or editormonkey_.