You need the following to copy 3DS/2DS data from one SD Card to another:

There is no limit on the times you can transfer data between SD Cards - and if you're computer-savvy, you can even go higher than the recommended 32GB barrier. Wondering how to upgrade the standard SD/microSD Card that came with your 3DS handheld to a bigger one, such as a 16GB or 32GB? If you're low on space, you can replace the SD Card that came with your 2DS, 3DS, 3DS XL, New 3DS or New 3DS XL with another.