The same way you mate other dogs.
How Do You Mate A French Bulldog?
French Bulldog breeding quite often involves artificial insemination. Breeding should be carefully planned and supervised closely or someone could get badly hurt. Health, STD and even hormone levels tests are quite often run before a mating. Then comes the c-section and the difficult and exhausting attempt to raise the pups. Their difficult :-).
From behind of course
Get a girl or boy depending on the sex of the animal or dog leave them alone and in an hour take them apart