I absolutely love the Mario Kart Love Song, but it's a little too quiet in game... and I don't want to adjust the sound effects/music ratio just for one song.
1. Go to the "Channels" tab on the right. Tick the Alpha thing and click on that channel. 2. Choose the brush tool and choose the color black. Then with the black brush, color whatever you want transparent. Whatever you colored should've turned red. Since Peach's and Zelda's dress textures aren't +1 or +2, making them transparent should be the same thing.
Picture:
The little blur in the bottom left says, "Oops, make sure this is black."