Hello my name is Jeffrey and I work for ASUS Customer Loyalty Team
If you have the right equipment you can change the cpu or you can take it to a technician and have them change it. They will have to heat up that one area of the CPU and remove it carefully then they will have to get the new CPU and put that one on without getting and solder bridges. Once that is done you have to test the motherboard to make sure that they have not lost any of the other small components and that there are no compatibility issues.
The best thing to do is to purchase a motherboard with the specs that you are looking for. Laptop were not meant to be upgraded that's is why they have desktops so you can load it up with everything your heart desires.
Might be even cheaper just to get a new laptop. These days laptops are pretty affordable.
Laptops are very cheap, but not compact ones. I have been lucky in purchasing this UL20A (that i consider compact) very cheap, because i stick to Asus laptop since 3 years 1/2, so regarding compact laptops below 13" and equipped with Core2Duo CPU's of +2Ghz, the price goes very high quite easily.
I am only targeting reliability of the mobo. (Asus is known for that), and the CPU specs, as for graphics i use an external graphic card extension device.