I want to replace the power jack on a Gateway M305CRV but I cannot remove the cover because the heatsink/fan assembly is holding it in place. The heatsink/fan does not seem to be removable as it appear to have 3 screws holding it in place from the bottom of the motherboard which is inaccessible. How can I remove the motherboard to replace the power jack? I cannot find dis-assembly instructions for this model laptop.