Wheel nut / threaded pen Outback mj 2018

Tach together, since last winter I have been driving (and screwing) after more than 20 years at Subaru. Should be an all-wheeler, but not a thick terrain bib. On the highway was also important. The outback is brown, in this with all the equipment and really nice. A bit quirky, but a force in the winter. For that I gave a 210 Mercedes station wagon, which I almost miss a bit. But only a little bit. Now I have the summer bikes at Subaru today made and found out that Subaru does not use any wheel screws – shortly after the astonishment I put a nut on the first wheel and killed the same with a threaded pin. Therefore, my first question here: are the threaded pins and how are they fixed or how do you change them? Really a very, very strange construction… Who can help? Many greetings Mika