Actually...
You can transplant the mounts, you can even mount the Nikon directly to your SLR without modification if it is a PRE-AI lens. I have done it recently and shot with my 50mm f/2 Nikon on my Pentax DSLR. It works like M42 set to manual in that you have stopped down aperture and you treat it like a preset. You have to be very careful as it only turns about 1/8 of a rotation in the mount before stopping. Some people have drilled recesses into the Nikon mount to ensure that it locks in this position or just swapped the mounts out entirely. When swapping you can add a small shim to make the Nikon perfectly focus at the right spot - otherwise Infinity might be slightly off - showing up in the finder before the focus scale reaches it.
The key is that Nikon's mount distance is just barely larger than Pentax - not enough room for an adapter but close enough for a mount transplant. You can also get the Adaptist mount for your camera in which case you need only use a shim and it will mount the Nikon more securely.
Flickr
Completely misread the original question. I have heard of the reverse of what I posted above where a Pentax mount is removed and the lens is shaved down and a Nikon mount added but this is major surgery and not really necessary. K mount can easily be adapted to work on a Sony, an Olympus, a Panasonic, a Samsung, a Fujifilm, a Canon, or a Pentax if you need to use K mount glass.
Last edited by UncleVanya; 09-30-2015 at 02:22 PM.