There are many laws and recommendations that are related to the specific requirements and interests of students with disabilities and govern affirmative action. 

Students with disabilities who are applying for a degree programme with admission restrictions may increase their chances of admission by submitting an application for exceptional circumstances.

• Härtefallantrag (hardship)

In accordance with Section 14 of the Lower Saxony Higher Education Act, the long-term study fee may be waived on application if the student can provide evidence of a disability or debilitating illness.

This application must be submitted to the Admissions Office by one month after the end of the lecture period at the latest and must include sufficient evidence. Usually, evidence from an official medical examiner is required.

• Langzeitstudiengebühr (Exceptions, hardship, guidelines)  

Alternative examination arrangements may be made for students who cannot take part in the examination in the form specified by the examination regulations due to long-term or constant physical restrictions or disability, to ensure that there is no disadvantage to any individual.

These decisions are made on an individual case basis in consultation with the Examinations Office and the examiners. In specific cases, students may be allowed more time in examinations or assistive equipment such as a laptop computer. However, such arrangements must be made under the principle of equality.

Affected students must submit an application for examination support to the Examinations Office as soon as possible but no later than three weeks before the start of the examination.

The Student Administration and Social Welfare Organisation (Studentenwerk) provides guidelines for lecturers with information and advice on making arrangements for students with disabilities.

• Examinations Office
• Guidelines for lecturers

Here is a list of other useful websites related to studying with disabilities (in German): 

• Bundesarbeitsgemeinschaft Hörbehinderter Studenten und Absolventen e.V.
• Bundesarbeitsgemeinschaft Selbsthilfe für Behinderte
• Deutscher Verein der Blinden und Sehbehinderten in Studium und Beruf e.V.
• Informationsstelle Studium und Behinderung des Deutschen Studentenwerks
  
• "Medien zur Teilhabe am Arbeitsleben" der Bundesagentur für Arbeit [pdf]