Cannot get data from participants into oone file

I have 500 participants in my survey that has an embedded experiment. I cannot get the data from the embedded experiment to analyze all together and get one output file. Can someone please help me? I watched the tutorial video, and I uploaded a file and adjusted the numbers per the directions on the experiment page (WCST). But now when I analyze, it will only give me the output of the one file, and it will not let me upload multiple files. (I have 500!)