How to upgrade to an i7 processor in your old laptop

Come along as I upgrade the processor in my old laptop that was originally purchased sometime in 2011. It was a cheap laptop that probably cost $250ish new. The upgrade to Windows 10 a few years ago rendered it very slow and sluggish. Everyday tasks were painfully slow. Editing a single youtube video was an all-day affair. I upgraded from the original i3 2370m processor to an i7 2640m. It was a big improvement, but I wanted something with more cores and more threads, so I ordered an i7 2920xm processor. This thing was a beast... but I decided to try one more... I made the jump from 2nd generation to a 3rd generation chip, the newest that my motherboard socket supports. The 3840qm processor is 2.8Ghz base, 3.8Ghz turbo, has 4 cores, 8 threads, and has the more efficient architecture of the 3rd gen chipsets. Any more than this and my pc will probably overheat badly when compiling and rendering video. Multitasking is no problem now compared to the chore that it had become with the factory installed 2370m.