One problem with that layout, the green resist coating will prevent capillary action from drawing the solder through the vias (feedthroughs, whatever you want to call them). I'd suggest a via right in the middle of each of the bottom-side pads. That way, when you apply the solder to the via on the topside, it will flow easily to the pad on the bottom. That of course means that the original SMD would have to be either bigger or smaller than, or offset from, the new one... you wouldn't want the pads to overlap.
The picture you showed is very much what I was thinking of in my original suggestion, but with blobs of solder on the bottom side instead of springy little contacts like I had in mind. I'm guessing that for a permanent installation, what you showed is more appropriate, and certainly more durable. In that case, you wouldn't apply any solder to the vias- just a soldering iron. Be sure that the manufacturer knows not to put that green solder resist material over those vias. I'm not sure Eagle will let you make a resist mask; I haven't done any PCB design with it yet.
Reflow is the process by which SMDs that have been secured in place with glue but not yet soldered are soldered in place in a manufacturing environment. The pads are pre-loaded with solder, and the SMD part is glued in place with a dab underneath, with its contacts on the solder on the pads. Then the board assembly is run through an infrared furnace that melts the solder and solders the SMD in place. Provided you know exactly what you are doing, you can accomplish the same effect with a soldering iron, once the SMD is secured (as you no doubt have reason to know).
Run the layout past us. I'll try to remember to comment.