Copy and paste the file to your computer. For ease of access, try pasting it to the desktop. Simply right click on the picture file and select "copy." Rest the mouse cursor on the desktop, right click, select "paste."
Now when you get to the part where you're downloading your file to your profile, and it asks where to look tell it to look on your computer, and select "Browse." The browse menu will include several options, and somewhere to the left will be an option to have it look for the photo on your Desktop. Tell it to do that. When you look there you can select the file you saved there for that purpose. Select it, then tell it to upload.
Hope that helps.