Convert color PDF to black & white PDF

Adobe Acrobat 8 Professional

• Double click the PDF file or you can open the file from within the program. Click File > Open.
• Click the "Advanced" drop down. Select Print Production > Preflight. Click the triangle that is pointing to the right next to PDF Fixups to see the Convert to Grayscale option.
• Select Convert to Grayscale > Execute. This will convert the entire document to black and white or grayscale.

Adobe Acrobat 9 Professional

• Double click on a PDF file to view the file or click File > Open.
• Click Advanced > Print Production > Preflight.
• Select the "Convert to Grayscale" option displayed under "PDF Fixups." Click "Analyze and Fix" button.
• Save the PDF file to a location such as the desktop to complete the conversion to black and white or grayscale.

Refer

• http://www.ehow.com/how_5588497_make-black-white-pdf-file.html
• http://blog.gilbertconsulting.com/2007/05/convert-color-pdf-to-grayscale.html