To join Kenyatta University as foreign or international student, all you need is ensure that you meet the minimum academic qualification requirements of the course you want to do and make your application online.
If your foreign academic qualifications are not in the list of recognized foreign academic qualifications then you need to have your equalization equated through KNQA (learn how it works).
Here is a list of KU courses and their requirements: http://www.ku.ac.ke/index.php/programmes
International students who are not from East Africa (Tanzania, Kenya, Uganda, Rwanda, Burundi and South Sudan) should apply through: http://international.ku.ac.ke/
If you are from East Africa apply through: http://applications.ku.ac.ke/