Starting point is at hotel Rosenlaui (1328m) where you can get by car or bus. Parking fee is CHF 8,- for 36 hrs.
There are two possible ways in the beginning:
First possibility is crossing the "Gletscherschlucht" which is a secured tourist path through tunnels and along balconies inside the deep canyon. This track has an entrance fee of CHF 7,- but that should be worth it since the community has a lot of costs every year to keep the track in good conditions.
Second possibility is the normal track around the "Gletscherschlucht".
Both paths meet after some distance.
Crossing the river via a bridge the trail heads up to the east until it splits up to go to Engelhornhütte left or Dossenhütte turning to the right (heading south).
To Dossenhütte it then is a nice and scenic walk through a glacier-valley leading steep up the moraine at the end of the valley, then turning up through a canyon, passing by the Rosenlaui-Biwak and from there scrambling up the last part pretty steep over rocks until the ridge is reached.
The hut is situated at 2663m like an eagle's nest on the ridge and very nice kept by Cyrille Zwicky.
From the hut the Dossengrat can be used to scramble further up until the foresummit of Dossen. There is a second alternative going up an icefield into the Dossenjoch. From there you can either go over the north ridge or turn around passing by under the westflank in order to reach the summit after that from the south.
Dossen summits are at 3138m (northsummit) and at 3144m (southsummit). The foresummit at the end of the Dossengrat before the Dossenjoch is at 3032m.
Gletscherschlucht link: http://www.rosenlauischlucht.ch/
Dossenhütte link: http://www.dossenhuette.ch/
Rosenlaui link: http://www.rosenlaui.ch/