The first 2 pitches aren't really worth doing, they're filled with lots of loose rock and the climbing isn't very interesting.
P1 starts in the obvious chimney and goes until a ledge is reached up on the right, the variation to P1 (variation of Mail Ridge) listed on this site is a much, much better way to do P1.
P2 climbs easy, loose rock to a ramp which you'll follow to the left to get around to the north side of the buttress.
P3 is the obvious slot to the left of Lightning Bolt Crack. Supposedly this is 9+, but I couldn't even get into the slot without pulling on gear! There's a thin crack in the back of the slot that you can get some jams in, but they didn't help me enough to get up into the thing.
It's also possible and probably better to reach the start of p3 by doing Dead Letter Department. You can get to the base of p3 in 1 pitch barely with a 60m.
To find this climb, hike to the popular Mesca-Line/Pony Express area, and just walk down from those climbs staying next to the wall until you reach a chimney, this is the start of the climb.
The usual Eldo rack, with a #3 BD cam that's perfect for overhead protection for getting into the slot of p3.