The constitutional court can declare laws Or parts of laws as not applicable and can require laws to be made and in specific cases it’s decisions are equivalent to a law (mostly regarding disputes which law applies, state vs. federal law, where certain responsibilities lie and in cases where the constitutional court decides that a law violates the constitution and is immediately declared void.) §31 BVerGG would be the applicable paragraph. There a nice summary in English on the courts own page https://www.bundesverfassungsgericht.de/EN/Verfahren/Wichtig...

Edit: added reference to the court page.