Topic: Switching Nintendo ID on 3DS. Possible to keep downloaded games?

My friend no longer needed his 3DS so he gave it to me. It had a bunch of games installed on it such as Starfox, Pokemon, and the like.
Problem Is, I have my own Nintendo ID that I would want to use for online play.
Is there a way to possibly back up the pre-installed games, Reformat to change Nintendo ID, and somehow keep those games?

The games are linked the the NNID. So no, if you change it to yours, the games won't work anymore.

That's weird considering you can play other people's games on your NNID on Wii U, as long as they have their account available on your console.

Well, not allowing you to play the games installed on the same system would be just plain mean.

However, if you unlink the account of the person who bought them, everyone else will lose the game too.