They must unsaddle the horse and bring the saddle to a designated point in the arena.
From the orlandosentinel.com
We unsaddle the horses and send the herd off into the forest, then sit down to an excellent dinner in the village restaurant.
From the guardian.co.uk
Interpreters were waiting at the end of the endurance course to remind the exhausted competitors to unsaddle their horses and go to the scales to be weighed.