If this is a Laptop it is very unlikely to change the CPU because there are too many things to worry about, like:
Wattage of your current CPU, with laptops it is NOT reccomended because of the Default cooler cannot handle another type of CPU if it is made for the Default CPU. But no you CANNOT unless you want to risk it, i suggest getting a new computer, I bet you hear that a lot in forums but i learned the hard way.