If done under warranty, they charge for the number of hours listed in the Nissan Service Manual to perform the task at the rate Nissan allows for the job, plus any parts and supplies that are listed as necessary to complete the service. If out of warranty, the hourly rate billed to the customer will vary depending on the dealer and the locale.
I don't know the actual amount they receive from Nissan. I would guess somewhere between $500 and $1500. There may also be additional funds for handling the battery, and the rental car for the customer to use while the work is being done.