The official entry point to the Carnic altitude trail proceeds from Alpenhotel Weitlanbrunn (the hamlet of Arnbach) initially via a wide forest trail, in flat hairpin bends up to 1660 m. Leave the trail here, bearing left. From "Hofer Bankl" the Carnic altitude trail is then also the route of the local trail. Follow the trail through the light-suffused mixed woodland area to the forest limits and continue to Sillianer Hütte. The Sillianer Hütte is closed in the summer of 2018 due to construction work, so you continue directly to the Obstanserseehütte.
Further ascent options to Sillianer Hütte:
1) Via route 471 and Leckfeldalm (4 hours walking time from Sillian, 2 hours walking time from Leckfeldalm)
2) Take the Vierschach cable car via Helm (2 hours walking time from Helm mountain station)