CPUs for laptops are designed to use as little power as necessary. They are also designed to generate as little heat as possible because of the difficulty in cooling laptop components in small tight quarters.
The memory controller and video controller are often integrated into the CPU.
The laptop CPU may be replaceable but are not often upgradable. Some CPUs may not be replaceable because they are soldered onto the motherboard.
Laptop CPUs are not up to par with desktop CPUs. They often run slower than desktop CPUs because of the smaller form factor and the fact that they must not generate too much heat.
To remove the CPU you’d first have to remove the fan and/or heat sinks on top of it. If there are number labeled screws, make sure to take them off in the order indicated. Make sure to wear an antistatic strap while performing a CPU replacement in order to prevent ESD.
Below is an example of how to replace a CPU on a laptop:
