For portable comuters the only 'Upgrade' available for the normal 'user' is memory. All else is out of the question as the machines are made totally inegrated, A hobbyist may well have a go for the hell of of it. But parts avbailability even for a hobbyist may well be the stumbling block. The 'Mobile' CPU for example is a different 'animal' to the regular desktop variety.
If you want it for games You are going to have to shell out a lot of Dosh. The upgrade rout is a wast of time. You have a Mobil CPU in it at the moment. If you did fit what you want it would be overheating