Select My Network and then select your Opportunity.
Select Actions | Edit.
Select Next until you get to step 5.
Scroll down to the Photos section and then select the + icon.
Drag and drop a file in the right panel or select the + icon on the right side to browse your computer for an image.
Drag an area over the image to initiate a cropping tool. Press Select to finish your selection.
Select Next until you get to step 6 and then select Save.