All the cable connectors on the motherboard are labeled as to what they are, and each cable is a different size and shape, so there should be no confusion when you reconnect. There are no screws to be removed in this process. Once all the cables have been removed from their corresponding motherboard connectors, you can now safely remove the motherboard. The motherboard is secured in place via a socket connector located on the under side of the motherboard. In this picture, more force is exerted with the left hand as is is closest to the socket connector.
Slight pressure is applied with the right hand to make sure the motherboard is removed evenly.
Pull the motherboard up and out. Be very careful handling the motherboard. You want to try not to bend or warp as this may cause component damage. If you do not think you are able to do this part, please contact a technician immedieately. Set the motherboard to the side on a non static suface.