I just had to do this on a rebuild of my Four Star. I filed down the tip of a piece of music wire (1/8" maybe) so that I could just force it into the hole on the flat side of the blind nut. Then I held the plane vertically and carefully fished the music wire up throug the fuse. When I got it over the hole, I threaded in a bolt from the front and tightened it down until the blind nut was pulled into the wood. It was an awkward, humorous process, but I got all four of them in without much pain.

I have also seen a method of putting the nut on the end of a wire and fishing it through, but I could not pull the wire hard enough to seat the blind nut into the wood.

I'm looking forward to Ken's suggestion. I'm sure it will make me feel like a dope.