Can North Korea open source its atomic bomb and missile technology (put all schematic and methods how build on internet or print books)? This is one way keep its technology by give technology to every person.
Yes it can in theory. But there is no reason to because:
Allowing anyone with the resource capabilities to make nukes is not a benefit for NK; their rivals and potentially non-state actors would now have access to the tech.
In fact it will make them be viewed as dangerously unstable.
It would also allow their rivals to see the limits of their capabilities.
Another point to add: The knowledge how to build an atomic bomb is a very old and common one, and you can in fact retrieve it from the internet. In fact, the principle is very simple: A mass of uranium/plutonium greater than the critical mass will detonate on its own. Just split it into two halves lower than the critical mass and push them together, for example by a small conventional explosion. It was possible with the technology of 1945 (and, in fact, it would have even been possible with technology from the late 19th century, if the knowledge about radioactivity and E=mc² had been available then).
The main problem is to get a large enough mass of enriched uranium and plutonium. Since you can't just buy this on the black market due to strict proliferation restrictions (really no one wants a group of islamistic terrorists to have such a weapon), countries like North Korea or Iran have to rely on own nuclear reactors to breed enough of the material to fabricate nuclear bombs. That is the main problem, not the knowledge how to build an atomic bomb. Maybe cutting edge technology is under seal, but anybody can learn how to build a 1945 Hiroshima style atomic bomb, and even this bomb type is horrifying enough to warrant nuclear deterrent.
Additionally to @oranges' answer, DPRK was specifically known for using its weapons know-how and products as a cash cow (notably, chemical weapons technology to Syria, and missile technology to Iran. Source: Arms Control Wonk).
Leaving aside Eric S. Raymondesque philosophizing over how open source can still generate money via providing services, in realistic short term, DPRK stands to lose any ability to generate cash flow by selling its know-how.
So, while it theoretically can, it most likely has another huge incentive not to.
The design of nuclear bombs is well known by now. It's the enrichment facilities to separate the scarce (and fissionable) U-235 from the much more common U-238, and the reactor needed to make plutonium that are hard to do.
With uranium bombs, just bring enough U-235 together, maybe add an extra shot of neutrons with an initiator, and it goes bang. The first uranium bomb used a short piece of a cannon barrel to shoot a plug of uranium into a larger piece of uranium to achieve critical mass.
A plutonium bomb only requires a ball of plutonium to be compressed enough, by surrounding it with conventional high explosives and setting them off at the same time.
However... U-235 is almost exactly the same weight as U-238, so separating the two is very difficult, either by electromagnetic centrifuge, or gasesous diffusion of uranium hexafluoride, a deadly and very corrosive gas. In both cases, the process has to be repeated many times.
Plutonium can be made inside of a reactor, but one needs a fully functional fast breeder reactor with the right type of nuclear fuel to do that. Since plutonium doesn't exist naturally, it has to be made in a reactor.
It is arguable that N Korea can be de-nuclearized by decommissioning their reactors and removing the uranium enrichment equipment. All of that can be reproduced, but it takes time and can't be done without drawing international attention... the equipment and expertise to set up both is very specialized.
N Korea may have had some help from Pakistan in getting its reactors and enrichment equipment set up.