Head on over to nwhikers.net and look in the trip reports forum, you should find all the beta you need.
Here's my two cents:
Take FS 2419 past the turnoff for the Upper Mt. Ellinor TH. I can't recall the exact distance but it isn't too much further past the fork, less than a mile. The bootpath begins on the uphill side of the road, marked by a boulder and a turnoff on the opposite side.
I've been up Route 1 a couple of times and it's a fairly straightforward scramble. There are a few places where route finding gets a little spicy.
There is a point about halfway up the way trail where you come out of the trees directly in front of a cliff. Do not mistake this for the headwall which comes much later. The first time I was up there we couldn't see 50 feet, we went left and ended up working our way up a gully system that required some terrifying Olympic 4th class moves on mud and loose rock in order to exit. Instead, head right and into the brush and make your way up through a tight squeeze between the cliff and the brush.
The ramp across the upper headwall is somewhat exposed but I've crossed it wet and it just required a little caution and some technical walking skills. Once you get to the notch above the headwall, it's a quick scramble up from there.