Probably not. Laptops have very specific Motherboard which will only allows a certain kind of CPU. Also, it is very hard and tricky to get to the CPU of a laptop. You need to the motherboard out of the laptop in order to get to the CPU which will require your to unscrew 20 very tiny screws and to mess up with keyboard connections.
If the two laptops are only 1 gen different or use a different CPU socket, then it will not work. So why don't you just use the new laptop ?