For what it is worth, there is another type of extractor sold here in the colonies by Snap-On but probably made by someone else (as it is sold under the Blue Point name, which is the brand that Snap-On uses for things it doesn't make>)
They are longish hardened splined shafts with hex-nuts that ride over the shafts to turn them.
You find the right sized one in the kit, tap it into the hole (or, in this case, the hex ) and turn it with the over-fitting nut.
They are REALLY good devices... work almost as well as a hardened torx bit tapped in to the hex
Mark
used them here. very good kit
outs" also splay the bolt, so making it even tighter 
