Trying to upgrade to Pro version for a 2nd website

I have Fotografie Pro on one website but wish to set up another website using the same web-design. I purchased a 2nd copy of fotografie Pro and tried up grade from the free version but the installation fails each time. this is the message Installing Theme from uploaded file: fotografie-pro.3.1.zip Unpacking the package… Installing the theme… Destination folder already exists. /home/domains/vol1/049/2776049/user/htdocs/wp-content/themes/fotografie-pro/ Theme installation failed I have followed the set up instructions Any thoughts ? Paul