To remove a module, all you need to do is visit the Modules page in the Form Tools administrator interface and click the appropriate "UNINSTALL" link. After you confirm this action, Form Tools will completely remove the module from your system - including deleting the folder structure.
Note: the folder may or may not be deleted, depending on file permissions. If it cannot remove all the files in the module folder, it will let you know that you'll need to manually delete the folder. If you don't delete it yourself, next time you click the "REFRESH MODULE LIST" button, the module will magically re-appear...
If you DON'T want it to remove the module folder, add the folliowing line to the end of your config.php file (found in the /global folder):
That will tell the code to NEVER delete module folders when they are uninstalled.