Here is how to claim them:
1. From the Nintendo 3DS HOME menu, select the Nintendo eShop icon.
2. Scroll left and select "Settings / Other."
3. Scroll down and select "Account Activity" to view a list of transactions.
4. The NES game will be listed here once it is available to download. Tap "Software Info," and then "Redownload" to begin the download process.
I can't wait!