2. Start Slowly
Generally speaking, you should choose a time after your dog has experienced some exercise, like right after a walk or after play time. Do not try to brush all their teeth the first time because your dog may not sit still for that long. Just get a few teeth and if your dog becomes agitated, stop and try again tomorrow. This is a marathon and not a sprint, so you should be able to increase the brushing time a little each day until your dog gets used to the sensation.
Reward your dog with a treat after each brushing so that they will actually look forward to having their teeth brushed. You may find your dog actually eager for each brushing as long as you reward them afterwards. You can even find treats that are both tasty for your pup and good for their teeth and gums.