By description, the Caucasian Ovcharka is a very intelligent, spirited, and strong-willed dog that can be a fiercely loyal family pet. However, they are very powerful and require an owner whose own strong will and sense of leadership is sufficient to assume the Alpha role. However, in the case of grooming, this may not be enough. You need to find a way to calm your big fella down first. One thing to keep in mind is that the younger you start grooming your Caucasian Ovcharka, the easier it will be to get him used to it and the less fuss he is likely to put up.
Around his family, your pup should be relatively laid back and relaxed, but around grooming tools he may be more than a bit nervous. The best thing you can do for this, is to start "grooming" him the day you bring him home from the breeder. This will start him out being groomed by you, which should help him remain calm as he gets older and reaches a point where he actually needs to be groomed.
Given that an adult Caucasian Ovcharka can reach up to 200 lbs in weight and up to 30 inches tall, you need to train him to remain calm for grooming from the outset. The last thing you or the groomer wants is to have to fight a dog this big just to groom him. Despite the fact they are very intelligent, they are also very stubborn, so reaching this point is going to take a lot of time and patience.