Black and white only

[Valtersson]

Hey guys.
I need help bad and quick.
I got a picture with some blue and dark colors.
I want it just black and white, I'm gonna print to a shirt.
Any tips?

[Illegalx17]

go into fotoshop, then hit control + u and the check the "colorize" box and make the saturation zero, or just hit control + shift + u