The CPU is soldered in, as all notebook CPUs are now.  Your existing system can be upgraded only to a faster version of the same generation CPU that you now have, and only if there is a system board having a faster 8th generation i7. If you want the just-passed 12th generation CPU, you need a new system. There is no way to upgrade your existing notebook to a 12th or 13th generation model.  
Good morning I`m trying to find the model of my laptop G3 15 3579 and unfortunately i can`t find it. I`m interesting in upgrading my CPU, from my i7 8th gen to something more new and looking around i found that i9 12900K is working on my laptop. So please can some one know anything about my laptop motherboard or if there is a possibility to change my i7 8th gen to an i9 12900K.   Thank you very much and i`ll look forward to hear from you.     
G3 15 3579 motherboard model and CPU upgrade