RapidMiner 5.3.015 needs to be patched to make the extension work.
1. Download the GIT-Patch and apply it to the RapidMiner project. Run the build.xml file from the root directory of your RapidMiner project using "Run as->Ant build..." and select "build" and "createJar" as targets.
2. Install the eclipse plug-in via "Install New Software" and using this update site. Rightclick the link and choose "Copy link location", then paste the link to the "Install New Software" window.
3. Download the RapidMiner extension into the "lib/plugins" folder of your RapidMiner project or install it from the RapidMiner marketplace.