Go to https://cat.eduroam.de.
Click on the blue button in the middle of the site.
Then select the College on the left.
On the next page you can select your operating system, the page tries to propose the correct system automatically. Download the program by clicking on the corresponding button.
Save it or directly run it.
Confirm the security promts and run the program.
Follow the instructions of the program.
Enter user name and password here. The user name is composed of the account name (E.g. abc123) and the realm of College @hnee.de (E.g. email@example.com)
eduroam should now connect.