I just used the "normal" steps I'd use for installing Subversion support in Eclipse Helios (3.6) which is the underlying Eclipse which Websphere Integration Developer (WID) 8 is based on.
SVN Team Provider:
- Help ▶ Install new software ▶ Available software sites ▶ download.eclipse.org/releases/helios ▶ Work with ▶ Helios ▶ type filter text: svn ▶ check: Subversive SVN Team Provider ▶ Next ▶ Next ▶ Accept, Finish ▶ Restart Now
SVN Connector:
- Open perspectve ▶ Other ▶ SVN Repository Exploring ▶ "Subversive Connector Discovery" should automatically appear ▶ SVN Kit 1.3.5 ▶ Finish ▶ Next... ▶ Finish ... ▶ Warning: OK ▶ Restart Now