Dear
@Ryan,
thank you for your question in the community.
Here is a link:
https://***.google.de/search?q=makler+d%C3%BCsseldorf&oq=makler+d%C3%BCsseldorf&aqs=chrome..69i57j69i60j0l4.4399j1j8&sourceid=chrome&ie=UTF-8
But I would suggest to you to go the governmental body in Düsseldorf that assist in such questions:
https://***.duesseldorf.de/buergerservice/aemterliste/organisation/show/amt-fuer-wohnungswesen-64.html
The Makler costs usually alot.
I hope we could help.
Best regards,
Nilab