At the bend behind the Adelshof hut (at the start of the toboggan run), follow the path through the snow on the right-hand side (signposted9). The route becomes wider after crossing the toboggan run, and after a short, steep section, you'll reach a path through the forest. The subsequent path is easy to climb to Birgitzer Alm, and Birgitzköpfl is at the end of the tree-free slopes.
To get to Birgitzköpflhaus, keep left befopre the peak and follow the ski path along the saddle. You'll reach Birgitzköpflhaus roughly 20 minutes after conquering the steep terrain from Birgitzköpfl.
To go back down, follow the same route before hitting the final third of the toboggan run.