On the HOME Menu, select ‘Nintendo eShop’ then select the account you want to use.
Select ‘Redeem Code’ on the left side of the screen.
Enter your unique 16-character download code displayed on the ‘Orders’ page of your CDKeys account or on the link of your confirmation email if you had purchased as a guest. Then select ‘Confirm’ to begin the software download. When the status bar disappears, the game download has been completed.