V-Ray/Blender consists of 2 components: exporter and custom Blender build.

• Install V-Ray/Blender Custom Build (exporter included)
• Install V-Ray For Maya Demo or V-Ray Standalone (check FAQ)
• Start Blender and select "V-Ray" from top menu

Now you are ready to use V-Ray/Blender!

If you don't want to use custom build you could download only the exporter in zip or tar.gz archive.

Extract folder from this archive and rename it to vb25, then move it to:
<blender-install-dir>/<blender-version>/scripts/startup/

Refer to Installation wiki page for more info.

More information: http://bdancer.github.com