Bought a used 3DS, can I change the Nintendo ID and keep downloaded games?
Solution 1:
The short answer is 'NO'
All games you digitally purchase from the Nintendo eShop are tied to the Nintendo ID used for purchase. As soon as you change the Nintendo ID in your 3DS/3DS-XL, the old games become inaccessible. The only way you can regain access to them through your Nintendo ID would be to purchase them from eShop using your Nintendo account.