I searched this method and my client did it, and it worked for her, so I did it, and it worked for both pairs! There were both tight (just the right foot of each pair). I need them to be larger right where the curve rubbed where my toes meet my foot; edge to edge. I did this and the both loose just right!
1) put water in baggie
2) put baggie in shoe
3) put in freezer overnight
4) take out, thaw a bit to pull ice out,
VOILA! New proper fitting edge!