I've produced a video that demonstrates how to get the PivotViewer Extension for RS installed (including the sample app) and help you get started.
Also, one quick (but important) mention (it's also part of the video): you'll have to explicitely unblock the PowerShell script in order to be able to run it (I've forgotten to sign it). The video demostrates how to unblock the script (really easy).
Here is the video. Make sure you view it in HD. Enjoy!