Start sitting at the base of the compression feature. Squeeze your way up. This climb is most doable in the ear- ly season, when the snow provides a great landing. Later it becomes an almost-impossible, bold endeavor.
Amazing problem. I did it twice. I used the kneebar at the bottom. We had about 9 pads and a decent amount of snow...it was still high. I think this one is more scary/pumpy than hard. It's worth just calling it 5.12