I have tried clamping down on the end of the insert with plyers but to get enough grip on the insert you have to pull it out and then you can’t get access to the spindle. or at least the sqared off part of the spindle.
I’m not familiar with the issues involving cranks like that with pedal thread inserts. Can’t help you much, other than suggesting a visit to your LBS (Local Bike Shop) and see what they say. They may know what can be done.
indeed the insert is spinning in the cranks, the insert has a splined interface that fits into the female splines of the crank, what has happened is through repeated bashing and shaking the female splines of the crank no longer exist, and the pedal moves freely almost floating in the crank.
hmm i might have an ideia u can tack it to a shop and get them to drill a home in the back of the pettle where is goes in the crank and them get them to thred the hole but mack the therd turn the opasit way and then boot a bolt in the hole and try to turn it out that way