Usual starting point is Etzli hut, it is also possible to use the Tresch hut (one hour longer). The actual starting point or the ridge is a saddle called Chlüserlücke (ca. 2750m). This saddle can be reached from east and west, but I describe the way from south which has become popular and which was opened by my wife's grandfather, Oscar Hug, who climbed it first in 1920.
From the Etzli hut (2052 m) follow the path to the Pörtlilücke (2506 m). This saddle can also be climbed from the west side, i.e. from the Tresch hut (1475 m). Then follow the spur to 2682 and finally to point 2824 m which is called Zwächten, due to the white shield of snow in spring. You may be tempted to leave the path before Pörtlilücke and to reach Zwächten directly fom Hubel 2416. I tried once but it took me much longer.
From Zwächten climb down to the Chlüserlücke. Now comes the best piece of the day: climb the Chlüserwändli, a face with solid Gneis rock that is easier than it looks from Zwächten. Then follow more or less horizontally the long ridge to the top of Bristen. Ca. 5 hours from Etzli hut.
Only a rope. When I climbed it first in 1950, a local inhabitant led me the way and he climbed barefoot (!) from Chlüserlücke to the summit. Plenty of tea.