How can I run World at War 5 on my laptop more quickly?

My son received World at War 5 for PC on Christmas Day. He has recently bought a Dell Inspiron laptop with a 2.1 GHz Core 2 Duo processor, 4Gb of RAM, an integrated graphics card GMA X3100 and a hard drive of 320 Gb. The laptop meets the game's system requirements as far as I can tell except for the processor speed, which it says should be 3GHz or better. Is there any way I can adjust the laptop or game so that it can run (it jerks so slowly as to be unusable)? If not, is it feasible to change the processor inside the laptop without it costing the earth?