Connect to the internet and download the Uber application on your smartphone. Register with your mobile number or with the Costa Rica sim you purchased for your trip. Save any required personal and payment information, and you are ready to book your Uber in Costa Rica. If you have downloaded the application before and have used it conveniently elsewhere, the same application will work fine in Costa Rica. It is best to have a local sim during your Costa Rica trip because, if you have one, Uber will let you call the Uber driver you booked even when you lose your internet connection.