Make sure you save the original version.

My preferred method is to insert the picture into a Word document (Insert - Picture - From File). Click on the picture and a small pop-up menu should open (the picture menu). If it doesn't open, right click on the photo and click on "open picture toolbar."

Adjust the contrast & brightness until you can see what you need.

You can also click on the photo and drag the corners to increase the size, if it seems too small to see.