I found a way to stretch shoes, but I have only tried on a pair of cheap no name pumps that I never wear anymore. I'm too scared to stretch my CLs to much.
Here's how:
Take a plastic Ziploc bag, fill with a little water. (If you are using a sandwich size bag fill with about 2 inches or so) The bag should fit snugly in your shoe. Add more water until it fits snugly. Make sure it's not loose! Put your shoes in the freezer for a couple hours or overnight if you want to make sure they really get a good stretch.
They will stretch because the water expands when it turns to ice. Try stretching your shoes little by little..you don't want to overstretch and damage your shoe! Good luck.