When we were kids, my sister got a doll's shoe stuck in her nose. My mother took her to the doctor, and he got her to sneeze it out. In this informative Lifehacker article by Beth Skwarecki, you'll learn a technique called “Parent’s Kiss”
Step 1: Use your finger to close the nostril that doesn’t have the object stuck in it.
Step 2: Press your lips over your child’s mouth.
Step 3: Blow a quick blast of air into their mouth (think back to the last time you tried to shoot a spitball through a straw).