Direct bus from Klagenfurt to Mallnitz, takes 2hrs www.postbus.at and costs 20euros each way
Train direct to Mallnitz then take the ski-bus to the ski-area a few km away
From Bad Gastein take the car-train which runs to Mallnitz.
From Salzburg take the A10 towards Spittal and take the Lienz Exit. Head to Obervellach then follow the signs to Mallnitz. 38km from the A10 turn-off
From Munich/Innsbruck take the 108 from Kitzbuel and take the Felbertauernpaß (small charge) to Lienz and take the 106 through Flattach to Obervellach, then follow signs to Mallnitz
Nearest airport is Klagenfurt about 2hrs away. Take the bus from there