Once you are familiar with FTP, uploading your ProPhoto theme files is actually quite easy. Go to the prophoto3.zip file on your computer and unzip it, thus creating a folder called prophoto3.

(If you ended up downloading the zip file multiple times, resulting in a prophoto3.zip and a prophoto3 (2).zip on your desktop, make sure you unzip and use the prophoto3.zip file.  If you try unzipping and using one of the other files, it can create a folder named something other than just ‘prophoto3′, which will create problems for you.)

Using your FTP program, navigate to the directory containing your blog files, and then go to the “wp-content” > “themes” directory. If you had problems auto-uploading the theme and there is already a ‘prophoto3 folder in the themes folder, just delete it.

If you have this problem, upload the inner 'prophoto3' folder

Then just upload the prophoto3 folder from your computer into the “themes” folder in FTP.

Your ProPhoto3 theme will now be available to activate in your blog’s admin area under “Appearance” > “Themes”.