At the top right of the lesson page you can click "test out" of that lesson.

i personally haven't done the spanish course yet, but in the spanish course there are sections that look like you can unlock them in large portions at a time. I think that will probably be coming to the german course soon. If you haven't already, you should take a look at the spanish course, just to make comparisons.

I have looked in earnest for the "test out" icon or button to not avail. I'm working at a level which is much too elementary. Help! I've looked at the FAQs which explain 3 ways to skip ahead or test out, but I'm just not seeing those keyholes or buttons or icons. Did they change something?