From the B111, turn at the sign “Gasthof Michal” into Gundersheim (left coming from Hermagor, right from Kötschach-Mauthen).
Then take the first road on the right. After about 100 m, the chalet is straight ahead.

Winter if snow (this season):
Do not take the first road on the right, but the second, then turn right again immediately.