no need to reinstall windows.
make sure the BIOS supports the new CPU.
use DDU to remove all the Graphics Drivers from the system if you are using the onboard GPU, reboot to safe mode and remove them again. if using a dedicated GPU and not the onboard at all DDU step can be skipped.
shut down the system, remove the heatsink and then the old CPU, insert new CPU into the socket and apply the new heatsink, if re-using the old heatsink, remove the paste, clean the heatsink, and reapply paste, then attach cooler to the CPU.
Boot up the system.
words in italics later added for clarity