Ok - it would be best to get this OUT of the pup!!
To make him vomit, you could take your dog to a veterinarian immediately as this is the safest possible option. If this is absolutely impossible, you could attempt it at home, but know that there is some small risk of aspiration of vomitus.
You can make your dog vomit by using 3% hydrogen peroxide.
Give 2 teaspoons per 10lbs body weight. If your pup weighs 40lbs, that would be 8 teaspoons, or about 2.5 tablespoons.
Tip his nose to the ceiling and pour it down his throat with a shot glass, or a turkey baster. To do this, hold the dog between your knees with you kneeling on the floor. Have the dog face away from you. Point the nose to the ceiling, open the mouth and quickly pour the FULL dose into the back of the mouth.
You can repeat in 10 minutes if he has not vomited yet.
More here: http://www.petplace.com/dogs/how-to-induce-vomiting-emesis-in-dogs/page1.aspx
I find the shot glass method to be the most effective!
If you are not able to give it by mouth as described above, you can use the following method:
1. Feed a small meal or slice of bread first - they are more likely to vomit with some food in the stomach.
2. Dogs will often drink peroxide if you mix it 50:50 with milk or ice cream, and it is just as effective.
3. Dogs are more likely to vomit after getting hydrogen peroxide if they move around - play ball, go for a walk, run up and down stairs - as this heightens the fizzing.
4. Always check the expiration date of the peroxide. If it is old it doesn't fizz very well!
Let me know what happens!