When you have to pop a pimple, you need to do it correctly so you do not cause scarring. You will first need to make the pimple area dry by applying some benzoyl peroxide to the pimple. If you wait about 30 minutes, the pimple should be ready to pop.
Once it is dry and your hands have been sterilized. If your hands are not clean enough, then the infected area could get a lot worse and cause a huge scar. Make sure you wash your hands first.