The hike is not too bad. We started at Climbers Bivouac (3700 feet). You start with a 1,000 foot gain through forest over ~2 miles. pretty easy. The more difficult part comes once you get out of the forest. You gain about 3,500 feet in 3 miles with no real flat parts or places to rest. Boulder fields that in places require hand over hand climbing (but nothing technical). The "trail" if you call it that is pretty simple. They put posts every 100 yards or so up the path with reflective tape on the top. you walk from post to post. That gets you to the rim. Then you have about a quarter mile to the true summit (walking along the rim). That is a bit tricky in places as you are side hilling the rim in really loose stuff. a fall would slide you down 300 to 500 feet or so. pretty much like falling on a sand dune, so you can't hurt yourself (unless you fall to the crater side in which case you die!). We had one guy in our group who did not like heights so that was a little dicey for him.
Very doable mountain though. even a fat guy like me who's idea of cardio is typing can do it!
Here is a map of the hike.