From the saddle north of Amphitheater Lk, descend the ledges into Glacier Gulch. Stay close under the N face of Disappointment Pk and head towards the toe of the E Ridge of the Grand. Climb over the moraine and cross the nearly level glacier to the obvious Koven Couloir. Ascend the Koven or the slabs to the left (or a combo) to the notch between Owen and the East Prong. Make a sharp left and follow the ridge, ascending a rock step by an obvious chimney or the ledges on the right, to the snow band called the "Collar."
Circumvent the vertical nose of the east ridge by traversing on snow either south or north (my preference) 200 feet to weaknesses in the cliff. Gain the crest of the ridge and follow it to steep slabs which are climbed on small holds for 25'. This slab is mildly RO but protectable. Traverse left to easy rock at the summit.
Descend by rappelling and down-climbing the route or by descending the easier Koven route. The Koven Couloir is best rappelled on slabs to the west of the couloir. Numerous rappel stations exist (slings.)
Take the Amphitheater Lk trail from the Lupine Meadows trailhead. The approach crux is finding the most efficient way to surmount the Teton Glacier moraine - right at the toe of the East Ridge of the Grand. Any other line will involve tons of loose talus.
Light Teton rack to 2" is sufficient. Long slings are wise. Carry some extra long slings for rappel stations.
Ice axe, crampons & helmet are necessary.