How do you show broilers?

I dont believe there is a category in which to show broilers at a sanctioned show.

However, if you can, you would show them like any other chicken.

Another view:

In 2010 the Sydney Royal Easter Show started a category for exhibition of broilers by school students.

"The Meat Bird pairs Competition in the School Section has been revamped into a challenging competition for schools to compete on a level playing field in the area of growing on trials of commercial meat chickens. The results of these trials will be judged at the Sydney Royal. This competition has the potential to grow into a very healthy challenge for Schools.

The Meat Bird pairs Competition will give Students an insight into modern Poultry genetics and also basic Poultry husbandry."

It was just like showing other chickens, but as this was a 'pairs' competition the two birds that were most alike were selected. We also had to have several options as they were sent to the show at a large size, so there was concern that one might die before the show and mess up the choice. We did have some trouble keeping the birds nice and white as they were spending a lot of time sitting down and this messed their feathers.