some laptop help

first i want to know if a processor is attached to the motherboard and where can i buy an dell xps m1210 hn110 model mother board it has an nvidia geforce go 7400 igpu in it not the intel board which i have since dell xps m1210 has only 2 interchangable boards and the nvidia 7400 gpu is much better than an intel gma 945

 

Then how do you upgrade an laptops cpu b/c i wish not to over clock and blow my system