Just completed trek to Indrahar in the month of May (2018). I must say that guide is absolutely necessary with all the equipment (rope, harness etc). This is because there is still snow on the mountains at least up until June/ July and the trek (specially descend) gets really slippery. A slip of the foot here can mean a certain death. So please take a guide and hire a professional with all the paraphernalia. Do carry gloves & torch as well as the climb and descend to Illaka have to be completed on the same day making the trek almost 12/13 hours long. Most of my fellow trekkers had a close shave with death due to slippery ice (ice and grass becomes slippery due to melting snow during afternoon and the fall is very steep). So be careful. I would rate this trek as very difficult.
Yes, you need a guide for Indrahaar Pass.
Reasons as follows :-
1). Indrahaar is not done by many , so the trail is not well marked.
2). The trail consists of Big rocks and Boulders which make the way very tough and if you follow the wrong trail you might end up to other place.
3). There are 3 summit at the top, Camel peak, Indrahaar pass, Moon peak and the trail is same for all, and the shepherds or guide knows the exact trail.
4). I have seen people doing the trek in late night, which have cost there life in danger, and the guide knows the weather conditions, because being a local they can predict better.
5). The weather will change in seconds, so if the trail is not visible, you might end up lost in different directions.
That sum ups the all points.
If you still want to go Solo, then plan to reach Indrahaar by 11:30 A:M, because after that the weather is not good.
In my case, the clouds were blocking the way and there was continuous rain, when I was descending it.
So it’s a tough trek overall and if you want to listen your heartbeat, then try it once, last 300 meters will be very tough, being stairs.
If you want any assistance in terms of guide, let me know, I will let you know the cheapest guide for Indrahaar.
Have a safe trek.
Thanks !!