no not the government - the constitutional order - but yes. You can legally get rid of the government and elect someone else, you cannot legally get rid of the things set out in articles 1 and 20. Of course if 90% of Germans would agree on getting rid of the constitution and making a new one I don't think this constitution would survive...Interesting, so if 90% of Germans decided they wanted to change the govt they would all be basicly traitors?
Edit: actually: treason is not the right word. I would have the right to resist this, as has the government - whether it would be treason would be a different story. The organization that promotes this would be illegal, what the individual actions would be would be a whole other story...