The CPU is likely soldered into the motherboard. The best possible CPU that the M5040 can be physically installed is the AMD E-450. However, #1 that's assuming the current CPU is not soldered into the motherboard, #2 the motherboard's BIOS will recognize that CPU. Just because it can fit into the socket, it does not mean it will work.
Your best bet is to return it and look for a more expensive laptop that is better equipped if you are not happy with your purchase.