You don't really need to do anything complicated for this sock toe.
Its basically use a hair dryer or some heat source.
Use heat all around the toe area so it unglues as best as possible.
Then you can use a flat screwdriver or whatever you want to pry the toe area away from the grey soles.
Once you've done that, you simply need to remove the grey fabric from the pink cardboard, and unstitch the grey fabric.
You will see that the grey fabric is tightly glued together, but if you steam iron the fabric or use a hairdryer, the hard/flexible piece thats in the toebox goes soft.
You can seperate the two grey layers of fabric for the toebox and if its still warm, the hard/flexible piece thats in there should be soft and easily removed or peeled off.
You can then either leave the 1mm foam fabric thats glued to the layers of grey fabric if you want ultra thin sock. Or you can just leave it.
Either way, you will have grey fabric thats much more stretchier than if you leave that toebox/flexible piece in there.
You can then cut off however much excess you want and glue the grey fabric back. The key is not to cut too much off as you don't want to stretch the grey fabric too much before glueing back.
I've seen numerous toebox modifications where the grey fabric is abnormally stretched, and the grey soles are sort of pulled back after being glued.
I always push the grey soles forward, and let the grey fabric be loose enough so that it easily glues to the grey soles without distortion.
Alternatively, you can just steam iron and have some muffin top. On larger sizes, muffin top is less noticeable so might be more acceptable if you don't or can't be bothered taking it apart.