because i'm lazy ... i'm not so much downloading the file myself, i'm going off of an assumption.
The trick would be to read the code and find:
If they're left blank for you to fill, then fill them
but to make the actual database you'll need to make sure you website people have access to all that jazz.
My thoughts are not to touch the php, but see where it's sending the information (like a feild for images and stuff like that). Then if you want to make your own look, use html or flash or boobie-shop or whatever (I made boobie-shop up). but make sure wherever the php is set up to put stuff (or react to stuff) include that in the file.
But yeah, leave the program alone, unless you know it already and want to tweak it.