Upgrading my laptops cpu?

no sadly you cannot upgrade laptops other than hard drives or RAM. Also if u wanted to make it faster I suggest getting an SSD, which technically is like 5 times faster than a hard drive.
 
actually you can upgrade the cpu in some laptops

have done it in the past where the cpu has failed and the only ones i had handy were faster ones

the bios must support the new cpu

but the more obvious problem is more heat is generated which isnt good in a laptop

so technically yes it can be done but as already pointed out an ssd would be a better option

especially if you have a decent enough cpu already