The DLC is available as a separate purchase, of course, but it is also part of the Nintendo Switch Online Expansion Pack subscription — if you're subscribed to that higher tier of Nintendo's online service, you'll automatically have access to the new DLC tracks in Mario Kart 8 Deluxe.
However, access to the pass doesn't simply 'appear' for Expansion Pack subscribers, because that would be too easy.
How to access Mario Kart 8 Deluxe Booster Course Pass DLC - Nintendo Switch Online Expansion Pack subscribers
In order to access the new DLC tracks, you'll first need to update the game software to version 2.0.0. This is necessary whether you bought the DLC outright or are a Nintendo Switch Online subscriber.
This update may have occurred automatically depending on your Switch settings, but you can make sure by manually doing it — press '+' while the game's icon is highlighted on the main Switch menu and select 'Software Update' from the options.
Once that's done, you'll see the tracks on the menu when you browse the in-game course selection. However, they still may not be unlocked at this stage.
In order to access the tracks, you have to open up the Switch eShop and manually download the DLC. You'll be able to find it by tapping 'Mario Kart 8 Deluxe' into the search bar.
Nintendo Switch Online Expansion Pack subscribers will see the option to download — simply hit the on-screen button and you should now be able to access the new tracks in the game.
Note. You can tell if you have access to the DLC or not via the main menu by whether you have a tiny Starman next to the version number in the bottom left corner:
That's it! Easy, but not as easy as it should be, perhaps.
This article is part of our Mario Kart 8 Deluxe guide series, featuring tips, hints, tricks and unlocks for the best kart racing game on Switch. You can find the Full Character Roster, every course in the game, including the DLC tracks, and How To Download And Access the DLC itself.
We also explain How To Build The Best Kart, How To Unlock All Gold Mario And All Gold Kart Parts, How To Avoid Blue Shells, How To Farm Infinite Coins, How To Drift, Slipstream, And Boost, and How To Get A Rocket Start, as well as Explain And Rank Every Item, list every every compatible amiibo and unlockable Mii Costumes, explore The Difference Between 'All Items' And 'Frantic Items', plus give an in-depth explanation of All Control Options And Assists and How To Turn Automatic Steering On And Off.