Redefinir as preferências de um único aplicativo é descrito no artigo Como redefinir as preferências de um aplicativo :
Sometimes you may want to reset all settings of an app. This is often helpful when an app behaves strangely or crashes on start.
You can delete an apps settings using the command line. On OS X you access the command line using the Terminal app. Terminal is preinstalled on every Mac and can be found in
/Applications/Utilities/
or using Spotlight:In Terminal enter the following command:
defaults delete <application ID>
The application ID is in the form com.company.app. For example to delete the settings of Wokabulary enter:
defaults delete com.mrFridge.Wokabulary
to delete the Tincta settings enter:
defaults delete com.mrFridge.Tincta
Remember that this command will reset all your settings and you will need to re-adjust the applications settings.