Laptop CPU are not upgradable. there are forums out there that mods there laptop(Upgrading CPU and changing video card and so on) but do remember you will not get much help if anything happens because you have force a cpu/video card change that may or may not damge the laptop motherboard.
If their physical (dimension & pin) configurations are the same (check their specs) then you may upgrade it, but you also need to change the clock speed (frequency) for higher rate. Otherwise, you may not gain as much as you thought. When you have the same number of CPU cores, the benefits will depend on the faster clock rate and bigger cache size.