The entire hike takes roughly 5 hours (to ascend) and 3.5hrs (to descend) which in total makes about 10 - 11 hrs (for us it took 10:56) including the stops you make at different spots.

Bare in mind acclimatization is of absolute importance in such high altitude climbs and has to be done in order to aid your body go through what it has in front of it so don't try to conquer this beast in a single day unless you're one beast yourself. Take warm and cozy clothes with you and don't forget to hydrate a lot in advance of your climb and during it.

It's not hard whatsoever, just go prepared.

Wish you luck.