In another browser tab, go to: https://appexchange.salesforce.com/listingDetail?listingId=a0N300000016YT5EAM
Log In

Click "Get It Now" button

Click "Install in production"

Check the "terms and conditions" and click "Confirm and Install"

Login

Click "Install" button

Wait

Click Done

Package is now installed

Go to a Contact record

Click "Edit Layout"

Click Buttons

Drag "Upload Picture" to "Custom Buttons" area

"Upload Picture" button in Custom Buttons area

Click "Visualforce Pages"

Drag "showPicture" above the Name

Click Save