The side opposite the fan assembly should just slide out. If it doesn’t I really can’t tell without looking at it. If you can determine what case it is then google that case and there will be instructions on how to open it up. If not google the exact ID of the computer, name and model number, and look for those instructions. Sorry that I can’t help more.
If you can prove that the computer was advertised as a 6-core but is only a dual core then you can demand your money back. My son and daughter both work for Walmart and they both said if you have the sales receipt and possibly the shipping instructions you can get your money back. My son, a T&L manager, said it sounds like may have shipped you the wrong computer.
One last thought, I don’t know about your local computer guys but up here for the same amount of money you spent they could have built you a very good custom music computer with off the shelf high grade products.
I had made that assumption,that the panel slides out,but like I had said,it won't budge.As for returning the computer..well...I've had it for about a year and on the website,it said that it's not eligible for a return(but then-if in fact,it's only a dual core,I guess that warrants an exception to their policy).
However though...I've been wondering...according to my brother,a 6 core processor would have more than 2 RAM slots(which it doesn't) and since there's no website that can scan my whole computer..well...no way to confirm anything...unless of course,my brother is correct in his assertion.
By the way,the very same computer I had bought(Cyberpower Gamer Dragon GDA2800),is now going for $800!
http://www.walmart.com/catalog/product.do?product_id=15773571-Thom