Bromeliads grow with the ultimate sacrifice of life. When most Bromeliads finish flowering they die and produce food/nutrition for pups or baby plants. These pups will normally develop from the bottom of the plant. The mother plant dies as a means of food for the baby plants.
Once the mother plant starts to die you can prune back the mother to 1/2 of its size. This is an optional step and you do not have to do this. This will only help to keep the plant from looking untidy.
Once the pups are 1/3 of the size of the mother plant, they can be removed and planted separately. Once again, this is an optional step and you do not have to do this. The bromeliad plant will grow either way, and whether you leave it growing as a clump or split it up is purely up to you.
Happy Growing!