To the right of the rock-triangle is a large couloir. This couloir gradually steepens from 45 to 55 degrees. The last two pitches can be (probably are) mixed. You exit on the westridge and from there it's easy rock to the summit.
The most logic starting-point is the Bivacco Borghi, but it is also possible to climb from Bivacco Martinotti. The description is from Borghi.
Leave the bivacco in northerly direction and bend east towards the obvious couloir up to the glacier Ghiacciaio del Gran Crou. Climb this couloir (+/- 45 degrees) and the icefield above. Go slightly right and at the top of this icefield climb up to the ridge on the right. Decent on the other side and traverse underneathe the north face of the Becca di Gay. Continue to the bergschrund of the righthand couloir.
Becca di Gay North Face Couloirs
1. Aproach from Bivacco Borghi
2. Central Couloir
3. Right hand Couloir
4. "Our" descent
5. Original descent
Cross the bergschrund. The best place to cross it is probably on the left side (looking up). Climb up the couloir staying on the left side. The couloir steepens near the exit and there the climbing can/will become mixed for two pitches. Exit on the ridge.
Turn left and climb large rocks to the summit.
So, that was the easy part. The descent is harder to find...
We did not follow the route description at all. What we did it the following. We descended on the south-west side for about a hundred meters. On the right there was a red wall and we traversed a snowy ledge.
The "snowy ledge"
Right after this ledge follow the rigde and rappel for about 20 meters. You exit on a small coll. From there decent towards the north and decent the righthand-couloir.
Cross the bergschrund and find your way through the icefall directly towards the Bivacco or turn left and go around all the rocks and then go towards the Bivacco.
Your normal set of icegear. So bring icescrews, crampons, axes, V-threader, slings, etc.