You can't upgrade the processor without replacing the motherboard, with one listed in your notebook's service manual that may come with a supported W11 processor.
A PC not meeting all of the W11 hardware requirements does not necessarily mean you can't install W11 on your PC, but you would have to perform a clean install and reinstall all of your programs and files.
If you want to see if W11 works on your PC, you can make a bootable W11 USB installer from the link below.
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