Is a sony vaio desktop pcv-rx860 and I need to replace the hard drive but can,t open it.

Yes you can have a trick on the back of the case or in the top why dont remenber but make a very fine inspection of the surface and you will find a trick that you push and the side just fall off ok try it and you will get it thanks and good luck

You should bring it in to a store where they can help you. BestBuy is probably the best because they have GEEK-SQUAD. call them up if you want them to come to you. not sure on the cost, though...