Here is a really great article on why dogs jump on people so that you can better understand the behavior, along with tips to help your uncle kindly and humanely train the dog not to do it. Every dog is different and learns at a different pace, so be patient and remind your uncle gently to reward his pup for good behavior. Meanwhile, while he/she is learning the new behavior, you can help my moving to the dog's level and firmly handling him or her, and speaking in a firm tone with a NO when the dog needs to be reminded. Good luck!
Jestamine is correct: A good trainer is what you need. There is no quick fix. The first thing is teach the dog to sit on command and stay in a sit until released. There are many things he cannot do while sitting. It helps to have friends willing to help with the training. You can have the dog on lead when someone comes over until the dog is reliable. Visitors must ignore the dog if he jumps; no eye contact, no reaching to pet. Giving the command to sit gives you something positive to have the dog do, rather than shouting no at him, which won't work anyway. One method I have seen work is, when the dog approaches with jumping in mind, the jumpee gasps in horror as though the dog was covered in some horrible substance and turns away from the dog, hands up away from the dog. Every single time! If the dog does not jump, the person may speak to him kindly, but if he jumps then, repeat the gasping/turning away. Dogs do not speak English and are not born preprogrammed. You must remain calm and matter-of-fact when training a dog. Do not give a command you cannot make happen. Do not repeat yourself; you will teach the dog he can ignore you. Read "Don't Shoot the Dog" by Karen Pryor.
Consistently is very important in correcting jumping and other problems. Quickly correcting him each and every time he jumps on somebody is very important. He must never get the affection he wants. A number of things have been used. One of the most gentle is to grab his front paws and hold him up. No need for abusive methods such as the traditional knee to the chest, spray bottles, or step on his paws are fading from use. As part of the the trend away from negative methods, just step backwards leaving his front feet to fall to the floor. After a few tries, the dog may just stand there looking confused.
There are places for the spray bottle, but not for jumping easily controlled by stepping back. .
Kimball can be energetic without jumping on you. Stopping the jumping is your uncle's responsibility, and a sign that the dog hasn't been trained-which all pets should be. You might want to suggest to your uncle that he and his dog enroll in a basic obedience class, for example, one based on the Canine Good Citizen program. These classes are fun, and will teach your uncle useful skills to help him enjoy his dog more.
Animal shelters/humane societies are very interested in helping people have pets that are enjoyable to live with. Try stopping by your local shelter to see if they either offer basic obedience classes or have information about any in the area. Then take a brochure to your uncle.
Here's what sometimes works for me when someone else's dog tries to jump on me-I put up my hand in a "stop" gesture in front of the dog's nose as the dog approaches me. Then as soon as he desists from jumping, I say "good boy! (or girl!)" to reward the dog for staying on all fours.
When Dog jumps up on you,knee him so he falls back,[gently] use stern command like "down,"loud and firm. Have people take turns at this so he get's the idea that he is not to jump up on anyone. Use the spray bottle if it helps, they can be, but the knee has always worked on our dogs
Well when a visitor comes hold your dogs collar and pull it back keep doing that every time until it learns not to do it again. If when a person enters the room or house and you are not holding your dog and it doesn't jump up reward it with some form of dog treat.
I would suggest not paying him any attention when he jumps, but this won't necessarily work 100% of the times. Have a chat with your uncle, and maybe suggest training lessons for Kimball.
Grab it by the scruff of the neck with one hand and swat it's hind parts with the other, then with your hand still holding it's neck, pull it around to face you, lightly swat it's beak and pulling your hand back quickly so as not to incur a bite, Point your finger toward it's face and making eye contact say NO loudly. Release the dog. Do this each time it jumps, and fairly soon, It won't anymore.
You should NEVER strike your dog, ever. The animal will become "hand shy" and will soon cringe anytime he sees a hand coming near him. There is no need to hit or abuse your dog, there are many training techniques to be used instead making the animal "fear" you. They can be taught to behave because they want to please their owner, not make you mad so that you threaten bodily harm if they do not comply. The violent and abusive suggestions offered here by another blurter such as grabbing the neck and hitting the dog--please don't follow that advice, it's not necessary. Elementary and Amore both have really good suggestions for kinder training methods and taking the dog for obedience training is a great way to enjoy a beloved and well behaved pet.