Hiring is the one side. Firing is the other side which, unfortunately is necessary from time to time.
If you have less than 10 employees in Germany, firing is usually not a big problem. You are considered to be a small company and can hire and fire relatively freely.
Even if you do run into a problem, the usual severance that is paid in Germany is ½ a month’s salary for every year worked in the company. This is not a law and sometimes more is paid but this is a good rule of thumb to use.
A Managing Director or a member of the upper management of a company is also often not covered by the laws restricting letting a person go.
We are not lawyers but often can help with firing an employee within your company or business in germany. There are many pitfalls here. If needed, a lawyer should be consulted.