Well you can't change it as its soldered to the board unless you know how to unsolder and re-solder CPUs.
Celerons, Semprons, Athlons, Pentiums, Phenoms/Pii, I3/i5.i7, Bulldozer, Trinity are all faster than the atom, the atom is designed for low power consumption and good performance (2 factors that are hard to mix together).
Get a new laptop and sell your old one on ebay is the best you can do.
I do have a better one, its just that on work flights and trips, I don't DARE take it. I need this because its good for mobile use and has all my files. (its an Alienware laptop) I do know how to solder, It's how i made my pc