Convert a CMYK image to Spot color

I made this package design partially in Illustrator and partially in Photoshop. The client wants the design to be in spot colors. I know how to get spot colors in illustrator, but how can I make that in Photoshop? The image of the dates at the to left of the design was made in photoshop and has a lot of colors in it, I'm not sure if we can even get that in spot colors, is it supposed to be printed in CMYK itself and then the remaining in spot colors? Can you please help me out here. Thank you in advance


