i wanted to switch the heads on these 2 m1go figures, but i discovered this when i took the heads off the bodies. the flashing on the dada is attached to the body and goes inside the head... and the exact opposite for the semi ningen

what is the best solution for this? is there a good way to attach the heads to the new bodies?

I'd just put the heads back on their respective bodies... I think the work required would be messy and risky to the aesthetic of the figures.

+1...that could get real ugly.

I would just leave them original.

using a lighter is to melt them a bit so they get super sticky might do the trick though....... although probably the worst idea ever

Let it be, let it be...

I've never tried this, and just thought of it while sitting here this moment, so it might be a horrible idea. But you might use that insulating, self-expanding foam. Spray it into the torso and the head to make them both "solid". Then you could insert a dowel into the foam to act as a neck joint. Of course, you'd have to trim the flashing off the ningen head and dada body. The foam might also mess with the articulation on the arms/legs.
That's all I got...

there's no easy way to do it if you are wanting to preserve the articulation. one option is to remove the flashing and insert a large dowel into the head or the torso. you need a dowel that is a perfect fit or it's going to be wobbly. i don't know exactly how big the figures are, but i think you can find a dowel that will fit.

the problem with that though is you'll never be able to return the figures to their original forms. so if you're willing to potentially "ruin" them give it a go. otherwise leave them be

just don't do it...