There are a couple of tools available for removing classes and rulesets if you are looking to remove them completely.

• "Delete a Ruleset" wizard
• "Delete a Class" wizard

One word of caution, while removing the application and the specific rule sets / class using the wizards, please exercise utmost cautions about the dependencies they have . 

Considering the applications appearing in your app explorers, they are definitely mapped to the access group. So check them thoroughly before deleting. 

Adding to Carissa's points you can find the wizard through following path (Designer Studio--->System-->Refactor) .

Thanks,

Arun