If there is any display output interface (VGA, DVI, HDMI or DP), you can
remove your discrete graphics card (GeForce 550Ti). It is very possible that
your Skylake integrated GPU's performance is even better than the old nVidia
card.
I installed a Celeron G3900 on the H110-based HP Pro Desk 400. The integrated
graphics is the lowest-end GT1 level. But its performance is comparable with
previous generation GT2 and even GT2e (such as HD4x00 for IvyBridge/Haswell).
Your i5 6600K has much better integrated graphics than Celeron/Pentium, so
the integrated graphics is strongly recommended.
However, stay away from laptops newer than Haswell, because of the Boot
Guard.
