You get it to Level 35 and flip the 3DS is what websites say. But exactly what sequence do you do it in? Do you flip as it turns to 35? Flip after it hits 35? Before? Just give the sequence.
Flip it before it turns 35 watch a video http://www.youtube.com/watch?v=Lh_6-6zErmA (That guy battles with the DS down but I'm pretty sure you need to flip it before it turns level 35.)
The level it evolves at is 30. Upon level up flip the 3ds upside down and you will get Malamar.