Temporarily disable Eclipse plugin
Is there a way to disable an Eclipse plugin without actually uninstalling it?
(Eclipse 3.3 had a "disable" button but this is now missing from Eclipse 3.4+.)
Some plugins allow controlling their load-on-startup behavior. These will be listed in the preferences, under General → Startup and Shutdown. If the plugin provides view, you will need to close those views (in all perspectives) for this to work.
First enable classic update in preference under :
General > Capabilities, then go to Help > Software Updates > Manage Configuration to disable it.
Below two links for your information
This and this link can help you.
As mentioned in bug 224145#c34,
I don't see any way to enable stuff except for what is in the p2 UI. And I see no update stuff there at all - not even in the list of things to install.
p2 don't even seem to have enable/disable functionality, only install/uninstall.
In other world, in the P2 universe (since Eclipse 3.4), there doesn't seem to be a "disable" process, and the word was not used in the Ganymede Plan or Galileo Plan.