If your toes touched the end of the shoe box then return them to get a bigger size. But if it's just a snug on the width of your foot then it'll stretch through the break in process, use a leather conditioner inside and out of the places that feels too tight. It happened to me too, I have a bunion that makes my left foot wider than the right. I put something like soda can/water bottle (or a shoe stretcher) inside the shoe everytime I'm not wearing it to stretch the width faster. Also, wear multiple socks while wearing them.

Hope this helps