Bring a printout of a recent image from the webcam so you can carefully position yourself by studying the surroundings in the image. You should be able to just hang your head out the window for about five to fifteen minutes.
You will need to coordinate with a photographer, who will be sitting at a computer with a decent internet connection. The photographer goes to this webpage at a time you previously agreed to:
http://www.oregontravels.com/_roads/s_ORE140_BlyMountain_606.html.
Every couple of minutes, the photographer needs to press the refresh the webcam. When you appear on the screen, the photographer then right clicks with the mouse and saves the image (practice this in advance, so everyone is on the same page). To get credit for this cache: 1) geocacher needs to be CLEARLY visible in the captured image (no a speck on the horizon, not a blob in total darkness - someone should be able to look at the image and say "isn't that bubba?"); and 2) the geocacher needs to upload the above image to the cache web page with their log. All other entries that attempt to get credit will be expunged.
There is pleanty of space to park off the side of the road (to the west), so make sure you are clear of traffic and safe. Pay closer attention to clues in the picture than to the specifics of the GPS reading when deciding where to stand. In the foreground on the left side of the image (east side of road, just west of stop sign) is obviously the best spot.
The biggest trick is that the web cam image only refreshes about every ten minutes. Or it did last time I checked. Obviously, you want to be sure the cam is working, and the refresh rate is what you expected, before attempting this cache.