There are several old post about this. It's much easier to assemble everything without the extractor and then take a very small screwdriver or pick and pry back the plunger into its hole, drop in the extractor and then let the plunger go to hold it in place. You won't need three hands this way, you just have to be sure to insert the plunger facing the right way so that it is positioned properly to drop in the extractor. You can also remove the extractor by prying back the plunger and lifting out the extractor.