Itaru, the ability to control remotely a vPro ready system depends on the Intel® Active Management Technology (AMT) configuration so the first step is confirming if the system in question contains the AMT.
As the official word by Intel, so far, none of the Intel® NUC Systems based on Haswell processors include the regular AMT layer as found in previous Q5, Q6, Q7, and Q8 Series Chipset based boards. In few words, it is not possible to remote control the NUC systems you purchased through the AMT. This is a hardware layer embedded in the board so no external hardware can make it to work.
The Intel® NUC Systems containing the Intel® Active Management Technology that you are looking for is the DC53427HYE