The traverse is done from the north to the south starting at Cabane Aiguilles Rouges. From the hut go west to the aiguilles rouges glacier. Climb it and cross the plateau to reach a little col just north of the north summit.
The rock climbing is graded IV but mostly III and II G6 or ZS/AD. Total time: 10 hours from hut to hut.
A good description of the route can be found in the deuter guidebook wallis or in the SAC-guidebooks.
Here the ridge starts with a very loose bit. Soon it gets better but stay alert for rocks coming down from parties ahead of you.
On the north summit (this hould have taken you 2,5 h from the hut) the quality of the rock improves. There is a tricky part on the west side of the ridge. A part with loose rock and the routefinding is a bit more complicated. Half way a you reach the S-col on the east (arolla) side of the ridge. Some snow and ice is found here. The climbing keeps following the ridge and sometimes you will avoid difficulties on the left or right side. I tried to count but I never came to the fiftheen gendarmes mentioned in the guidebook. In the deuter guidebook the route is described by the number of the gendarmes. We asked the guardian about the route "stay on the ridge" was his advice.
Going back down is a long way through the scree not to mention the walk back to Arolla if you don't want to go back to the hut that is.
rope, quickdraws, nuts, friends, crampons