Editing in Photoshop

I first uploaded all the images i was going to use into photoshop 

Then i edited them to Desaturate 

I created a new blank file

 

I measured and cropped my images to the same sizes

I dragged my images onto the blank file

I zoomed in to line up all three images

I edited each image with a boarder of 15px 

I lined up each image so it was correctly in line 

I finished by cropping the image