Laptop CPU's are (generally) not meant to be upgradeable - in many cases they are soldered, and more powerful may need upgraded cooling, making the process questionable. The BIOS itself should also support new CPU.
Sony laptops are well known for worst support. Your laptop is probably ten years old, and BIOS upgrades are rarely available. To make the things worse, Sony no longer owns Vaio business.
Leave the old boy die its natural death.