^ Agree with above poster.
However, you should just be able to swap the CPU and have no issues.
Do you have an overclocking (Z170) motherboard? If not, the i7 6700 is cheaper, comes with its own cooler, draws a lot less power, and though it's clocked a hair slower, it will be unnoticeable. I would recommend an i7 6700 over a 6700K if you don't have an overclocking-enabled motherboard.