1. Open the Nonlinear Animation editor.
2. Enable the animations you wish to preview (checkbox on the right side of each track, next to the lock icon).
3. Select an Action Strip in the track (the named box to the right of the Animation Track name) by clicking on it.
   * _The selected strip turns bright orange._
4. Press the `tab` key, or right-click on the strip and choose `Start Editing Stashed Action`.
   * _The selected strip turns bright green._
5. Select the node in the Outliner that is affected by the animation. 
   * _Keyframes for the strip show up in the Graph Editor, Action Editor, Dope Sheet, and Timeline._
5. Modify the animation as desired.

The only open question for me is how to make step 5 less painful. Given an Action Track or Action Strip, how to I find the node(s) that it affects, or automatically select it in the Outliner?