Only did the easiest climb of the possibilities here myself, starting from Sattel (Brüggli) (764m). This is still not very easy, but a moderate climb never really above 10% apart from the last concrete (wheel-base only) ramp to Wildspitz (1564m) just below the actual Wildspitz (1580m) easily reached on foot from there.

Starting the climb at Steinen (centre) (472m) and then take the same road to the pass and the mountain would be more of tough climb. Better yet would be to take the road up to Wildspitz from Steinerberg (625m), but then you would likely be coming from either Arth (418m), Goldau (496m) or just outside Steinen (461m). This last climb should be hardest climb with a 9.9% steepness for almost 11 km qualifying it for inclusion among the reallly hard climbs, but I do not know the road, apart from the last part as the two roads up the Rossberg meets at the height of 1128m.

It is a nice climb with great views if you go all the way up to Wildspitz. I think it is fairly clear that a pass is located at the unnamed 1521m point before the last ramp. Here a gravel road continues to 1532m before descending on the other side.