Trying to get a file that the printer can use

I'm trying to create a file that my printer can use. I am trying to have some door hangers printed. They are black & white and one color (reflex blue).

The image I am working on is in CMYK mode, the printer said to only have black and 100% cyan in the file and save it to PDF to send to him. I've got everything figured out but my logo. The printer said the logo has to be in grayscale, because right now the file I send to him the logo is making it a 4 color job.

The logo is a separate file so I have been just opening it and dragging it into the door hanger image. I first change it to grayscale using Image/Mode/grayscale, but when I drag it into the door hanger file it somehow changes the logo image into parts of C, Y, M and black.

I'm stuck at this point in how to keep this a 2 color job?

my first thought is to just select the logo layer in the door hanger file and desaturate it.

generally when doing a 2 color job you'll create it as a duotone or a grayscale image with a spot color channel, seems a little odd doing it this way but its hard to be able to give more info without seeing the image.

chris