The walk from Ghoragali to PirSohawa is though not very tough but one of the longest one that Margalla hills offers. It starts from the village of Malot near Ghoragali which has an altitude of 1490m. It takes an hour drive from Islamabad to reach this village. If you want to use public transport, take the van/bus going for Lora from Faizabad in Rawalpindi. Direct transport right to the village is not very frequent so another option is to take the one going towards Murree through the old road (not Murree express way) and get dropped at Lora. Malot village from where the walk starts is further 2-3 kilometers from Lora.
The trail is in fact an abandoned jeep track on which jeeps used to run to and from PirSohawa. On a clear day, the trail offers some nice views of the valley that falls in Hazara region in the North and the snow capped mountains of Kashmir to the South. The trail passes through the villages of Danah, Karagga, Kimbi and Kothrian and eventually would descend to an open area with a small water pond. This place has an altitude of around 1140m. From this place, a jeep road goes north towards Gambheer villager. Skip the road going towards Gambheer and take the path that is going up towards west. After some ascend, you will reach at the top of the ridge with some nice points for rest. This ridge will provide some very nice views of the whole valley. From here on the trail on the whole remains very much flat with an altitude remaining between 1300 to 1400 meters. Continuing on the path will take you pass through the village Shiddan from where a left turn from a fork is not to be missed. Another hour or so from that point will take you to the Pharilla rest house. Pharilla rest house among pine trees is a very nice and peaceful place to spend a night if one intends to. From Pharilla, PirSohawa is another couple of hours walk away. After a few kilometers, a path towards left descends down to Shadra village and Quaid e Azam university. The main trail ends up on the road around one kilometer before main PirSohawa.
Another account of the walk by backpacker can be read here.
Total distance for this trail is around 25 kilometers and an average walking time is 7-8 hours.