If you haven’t seen it in the Eclipse announcements: Galileo SR2 is available for download from eclipse.org. From this page you can download the new EPP packages that are based on Galileo SR2 (Service Release) and Eclipse 3.5.2.
Or, if you don’t want to download the full packages, you can start an upgrade – that’s what I did just a few minutes ago. I started with an older working copy of Eclipse (probably something from Galileo SR1) and started the upgrade process (‚Help‘ > ‚Check for Update‘).
It takes a while until p2 fetches all the required metadata from several repositories. The list includes the EPP package repository with the package definitions, the main Galileo repository and the Eclipse Platform repository. A few Okay-clicks later, p2 started to download the new content and asked me some more minutes later to restart Eclipse. Et voilà – after that restart I had a brand-new Eclipse with the latest version without downloading a new package.