With all due respect to everyone here who guessed at how to remove the solder, they are all dead wrong. Do not attempt to heat the area of the solder with an iron. When coins are soldered in jewelry applications, the method is brazing and it is done with a torch or in an oven. The solder attached to a silver coin is almost always silver and is almost always hard solder, or .800fine. Soldering silver requires heating the entire piece to solder flow temperature because silver is the best conductor of heat of any metal, and heat sinking is difficult on anything other than light wire or shank stock. Removing solder from a piece of .900 fine silver whether it's a coin or a piece of jewelry should only be done by a qualified silversmith.
Also, be aware that heating the coin to the stage of red heat necessary for causing the solder to flow so that it can be vaccumed up with a bulb will also cause the copper in the alloy to bloom and the coin will then have to be pickled in a heated acid solution to return it to its silver color. Glazing the coin with a boric acid/ethanol solution will reduce the copper bloom, but will also have to be removed by pickling. Removing the solder is going to reduce the eye appeal of the rest of the coin which doesn't have the solder on it.
You should send it off to be restored or leave it alone, but trying to melt the hard solder with a soldering iron will not work and will cause discoloration.