Bama

We're having some t-shirts made up for an event and they've asked for the logo to be black and white (specifically said not grayscale).

I have the logo in these formats:
.eps
.psd
cymk.eps
.ai
cymk.ai


Which would be the best to use for the t-shirts and how the hell do you change a color logo to black and white?

Thanks,
Bama