From the parking lot for Dream Canyon (consult the Rossiter Dream Canyon or Boulder Canyon guides) follow the Lost Angel trail due west from the parking lot. Stay on the high trail as you walk down. This should bring you to an outcropping of rocks. Follow the trail down into the valley as it veers North. Look for a notch you can scramble though, climb down and then back up through another notch with trees. Down on the other side will bring you to the Lost Angel.
It is probably easier to head down the road from the parking lot take the 1st trail on your left. This will drop you off at the Oceanic wall. From this point head south along the river (you may get wet) until you start climbing back up the ridge. This is the Lost Angel.