Enabling, disabling, and uninstalling features with the update manager
You can browse and manage your configuration from the Product Configuration dialog.
Open the Product Configuration dialog by clicking
 Help > Software Updates > Manage Configuration.
Help > Software Updates > Manage Configuration. 
  - Disabling a feature: select the feature and click Disable
  in the right pane of the dialog.  This option is available only when the feature is 
  currently enabled, and the feature is either an optional feature or a root feature 
  (not included by other features).
- Enabling a feature: First, ensure Show Disabled Features
  is turned on in the tool bar.  Then, select a disabled optional or root feature and click  
  Enable in the right pane of the dialog.
- Uninstalling a feature: features that you have installed using
  the update manager can be uninstalled, provided they are already disabled, or that they 
  are optional or root features. If the feature is disabled, make sure 
  Show Disabled Features is turned on in the tool bar.  Select the feature 
  and click Uninstall in the right page of the dialog.

Features

Using the classic update manager
Installing new features with the update manager
Updating features with the update manager
Controlling the Eclipse update policy