Overlays in Google Earth -- Instructions, no Plug-In

I've not been successful in recording a tour which loads the Rumsey Overlay seamlessly. But it is relatively easy to do so manually in Google Earth. Make sure you have the most recent release which is Google Earth 5.

• Open Google Earth and fly to London
• Look to the lower left. Find "Layers"
• Uncheck all of the options except for "Terrain"
• Click on the "+" beside "Galleries"; Look for "Rumsey" collection
• Enable the Rumsey Collection by checking on the box to the left of it.
• You should now see a medallion in the vicinity of London: if not, zoom out.
• Left Click once on the medallion; a Placemark should pop up.
• Left Click once on the thumbnail of the map (you are instructed to do so in blue, but that's hard to read).
• The 1842 map should now appear as an overlay of London.
• It should also appear as a file in "Temporary Places."
• Highlight the file in "Temporary Places"; right click it and
  
• "Save to My Places"
• Now it is on your computer; when the 1842 map is checked, it will overlay modern London.
  
• Uncheck it, and the overlay disappears, but the file remains; the key is the get this file on your computer. The "Tour" tool can't seem to replicate this step.
• Now check it.
• Now move around London of 150 years ago!