From the camp near lake Lago Verde, continue about 500 meter up the valley. Locate a trail fork, the main trail heads (right) uphill to what looks like a col while the trail towards Humboldt forks left and ascends a short section of cliffs. These cliffs are just right of a small waterfall, sometimes you may see a bit of ice here. Climb this trail as it ascends the hillside, first steeply, then somewaht more gentle into what looks like a very broad, uphill valley. There is a moraine higher up, the trail climbs to the top of this moraine, then heads slightly right in order to continue the uphill climb on steps of rock that used to be under the now shrinking glacier. The terrain in this section is typically YDS class 2+, there are many alternatives. Stay right as you approach the glacier above, and locate a fairly distinct gully that leads up to a local col on the ridge above on your right side. This gully is most easily climbed by ascending the rock on its left side in the lower (steeper) section, then completing the ascent on pretty loose, but less steep gravel near the top.
This rocky ridge now holds the key to your advance towards the glacier. The ridge is wide and provides easy access (YDS class 2) to the edge of the glacier. Unless the glacier surface has turned to blue ice, one can trivially cross it and reach the base of the Humboldt summit area. This section consists of a short, but gentle uphill, then a flat crossing to the other side. (In the case of blue ice conditions, a pair of crampons would be helpful.)
The final ascent can be done along different routes. The easiest way is to stay right and gradually climb the ridge while advancing uphill. This is no harder than YDS class 3 scrambling. An alternative is to proceed more directly towards the summit and climb uphill while aiming for a pretty distinct crack higher up. This route has a (YDS) class 4 move near the top as the crack becomes deeper and quite narrow.
Either way, continue along an easy slope the last few meter to the small summit cairn.
Pico Humboldt was first climbed by Dr. Alfredo Jahn and L. Hedderich on January 16th. 1911. Dr. Jahn, a Venezuelan geographer, in this way marked the start of Venezuelan mountaineering. During the same trip as well as on a later trip in 1915, he also attempted Pico Bolivar, but was unable to reach its summit.