First Way

Open Photoshop.

Click File  and open the color picture which you want to covert into black and white.

blackandwhite

Click on “Image” – “Adjustment” – “Black & white“.

blackandwhite

Click on “OK“.

blackandwhite

 

Second Way

Click on “Image” – “Adjustment” – “Desaturate“.

blackandwhite

Now the color photo changes into black and white or Grayscale.

blackandwhite