We need full details of the current parts and the new ones before we can give solid help.
General issues:
Depending on motherboard you may just get away with an upgraded CPU.
Depending on what parts your system has and what you are purchasing you may also need RAM, DDR3 memory won't fit a DDR4 MB.
A upgraded power supply may be required.
Swapping the CPU and motherboard will, at the very least require a reactivation of Windows, if you have an OEM (builder) license it's likely you'll need to purchase a new licence-yet more expense-but this varies according to which Windows version you actually have.