As you near the base of Echo Crater, you'll have to bushwhack your way up to the rim. You can follow the GPS track or forge your own path. However, I would recommend following the track, as the view when you reach the edge is excellent. You can then pick your way down and into the crater itself.
All in all, this is a relatively easy trail, with the most strenuous bit being getting into and out of the crater.
If you spend the night, I recommend going down into the lowest point of the crater. Once night falls, the wind goes away and it is incredibly peaceful.
Get up early and go up to the eastern rim and watch the sunrise. Or don't—it's your adventure.