Approach

From the Konkordia Hut:
Descend the 100m of ladders to reach the Konkordiaplatz. Go NW along the level glacier for nearly a kilometre to reach the true left bank of the Emigschneefald.
Climb up the sustained slopes on the left bank, to the NE , avoiding a choatic area of the glacier which is to the right. Below Pte 3135m, the angle of the slope eases, continue northwards for 2kms on almost level ground.  

From the Mönchjoch Hut:
Go down, (easy skiing) until about 3200m where you join the previous approach.

Route

Go up NE on the right hand side of the glacier coming down between the two rocky spurs of the  Gross snd Hinter Fiescherhorns, passing to the N of Pte 3509m.Gain the base of a large and obvious gully coming down from the Fieschersattel between the two summits. (sattel = col)
Carrying your skis, cross the bergschrund and go up the gully/slope (40°) exiting on the left onto the Fieschersattel (careful of stones on the last part.)  Leave the skis at the col and follow the SE ridge to reach the summit.
It is worth climbing the Hinter-Fiescherhorn while you are here:
From the col go along (ski) keeping to the left under the ridge  Reach the ridge by a short snow wall (40°) and follow this to the summit.

Descent:

By the same route.
Variant 1:
From the bergschrund on can descend the true right bank of the glacier above a serac band coming down from Pte 3711m. Attention : this variant should only be taken in good conditions and visibility because it goes along a serac band.