Don't worry! It isn't painful for the puppy, even if it is horrible for you to see him that way. It is a common occurrence and is very, very treatable. Make an appointment, and take him to see your vet. Make sure he's a good, experienced Bulldog vet. Most likely, at this age, they might be able to be massaged back in. But once they come out, they'll probably keep coming out until a surgery is done. Options there are tacking it in, or removing the tissue altogether. I'm afraid that isn't a cheap procedure.
Warning: My bulldog has never had this, I'm simply sharing information that I've gleaned from the site over time. Others who have dealt with this situation will be far more knowledgeable, but I didn't want you to worry!