Right where the main road up the hill starts (it was widened to put in the electrical towers you'll see up the hill) you can go right up a steep hill, or follow the road: follow the road. It zig zags up the hill through eucalyptus trees, then continues more directly uphill to a gate. Go through the gate, following the road up to another gate with a power tower immediately inside it. Go through this, and keep following the road up the hill (it gets really steep here), to the top of the ridge, where the road bears left into the ravine you have been skirting this far. Keep on it (there's another gate here), and down the short hill (enjoy it, it's short...) to where the road starts a logn brutal climb into the heart of the valley directly below the Rucu Pichinca peak. When you get near the top of the valley there are trails that go further in, or left to meet up with the road along the other ridge; follow the main road right, as it zig zags up a steep slope to a peak opposite Rucu Pichincha. Surprisingly, this climb is easier than the straight shot up into the valley. When you get to the top of that ridge, the road peters out, but find the trail that heads higher towards a small peak; the trails skirts the peak on the north side, then starts to go down into a valley. On the far end of the valley (north west) you can see another sort of road leading out; head overland towards this, the trail seems to vanish here. The valley floor is essentially a swamp, too soft to ride in, but enjoy the walk as you carry your bike the 2km or so across some absolutely crazy looking terrain. Then follow the path/road you'll meet along the left side of the valley that opens to the north for a few km, until it heads west, and at this point, pick a likely looking slope at a spot where you can see a road below you, and just start heading downhill across the meadows. When you hit a road, work your way down and east, until you meet up with the main road that goes to Nono, which will take you back to town, and Avenida Occidental a KM or so from where you left it.
In Quito, drive north along Avenida Occidental past San Carlos (on the right) and the entrance to Atucucho (on the left). As you round the corner and the road starts to head down again, at a pedestrian overpass and light, turn left up the hill. This should be Barrio Sta Anita on the map. Work your way uphill through the barrio, and the road will at some point bear right across a narrow bridge. Go this way, then continue up the hill. When you see a church, go left, then right again at the end of that road, to continue up the hill. Leave your vehicle where the pavement ends.