Ive climbed the Dana couloir many times and skied it several times.
The approach is straight forward. Park at the Tioga Lake overlook and follow the trail up Glacier Canyon which begins with a short descent from the parking area. There are a few moraines with talus to cross before getting to the glacier proper but there will be no crevasse problems. This time of year it will be just firm snow and no bergshrund. People are probably skiing it. It's snow filled so less rockfall.
It's about an 800ft couloir at apps. 40-45 degrees; moderate in climbing terms.
Enjoy.
