Summarize the following:
Two pairs of thick socks should do the trick. Use more sock layers if you want to stretch your heels even wider. The goal is to make your feet thick enough to stretch the shoes, but not so thick that they will not fit. This might be difficult – but try to get them all the way in. Don't hurt your feet or crush your toes! If you simply cannot fit your feet into the shoes, then remove a layer of socks and try again. Now, heat the stuffed-up heels with the hot air from a blowdryer. Focus on the areas that most need a stretch. Wiggle your toes and flex your arches. Keep it up for 2-3 minutes until the leather is hot – but not uncomfortably so.  Leave your sock-clad feet in the heels until the leather cools. This way, the leather will cool around your slightly-larger-than-usual feet, and it will settle into a stretched position. Be careful with the heat. Don't let the leather grow dangerously hot. If the heat begins to scorch your skin, then take the heels off and try again later. Once the leather has cooled, try wearing the heels without the layers of thick socks. If they fit comfortably, then your work is done. If the shoes still need some stretching, then repeat the procedure until you're satisfied. If you want to break in the shoes a bit more: try bending them back and forth to loosen the leather. Then, blast with heat again for 2-3 minutes to wear in the material.

Summary:
Put on a lot of socks. Wedge your feet into the heels. Blow-dry your feet. Remove your socks.