Ich möchte mich juristisch weiterbilden. Geht das auch ohne einen Studienabschluss?

Yes, it is quite possible to continue your legal training as part of a postgraduate course without a university degree. Universities often give preference to academics for continuing, further training in law, but people with other qualifications and many years of qualified work are usually also admitted after clarification by the course management. However, as this is always an individual matter, you should contact the school directly and discuss your concerns and qualifications.