Solution: We just need to go to http://dist.springsource.com/release/TOOLS/update/e4.3/compositeContent.xml
and search the value of http://dist.springsource.com/release/TOOLS/update/3.6.3.RELEASE/e4.3/ (it can be different, because the release version may different)
Then go to Help > Install new software > fill the work with with the url you found before.
Done