Alienware CPU & GPU Upgrade

Is the CPU also upgradable on the Alienware 17 (Mid 2013) (<ADMIN NOTE: Service tag removed per privacy policy>)? (It has an Nvidia 860m 2gb gpu, and an Intel i7-4710mq).

Also if, for example, I get the 880m (I know from other posts about this computer it's been verified for this model. Not the 900m series though, unfortunately. :/ ) would I have to do it myself, or does dell offer a service to upgrade components? I'd rather not mess up my computer if I can get an 880m.

So essentially what options do I have for cpu and gpu upgrades and how do I approach it?

If I can buy these things still, where would I go? Just email dell sales support about it?