Summary: If it gets difficult to inform your institute/school teacher verbally that you would not like to continue with her, there is a better way out. Send them a letter explaining why you would not like to continue with him/her in a precise manner by following the below format.
Mr. Bruce William,
Allen Educational Institutions,
14 Hanging Street,
New York, USA.
Dear Mr. William,
We really apologize to tell
We regret to inform you that your employment with us shall be terminated, which has been decided by the Board of Directors due to poor teaching skills which has led to your students low percentage score.
Also, the parents of the children have contacted us regarding your poor behavior towards the children. Not just parents, students have also complained about your humiliating behavior and situations where they have been embarrassed in front of other students. The reason of your termination is the constant feedback from students and parents about your behavior and teaching skills. Due to this, the college has decided to dismiss you without giv ing you any prior notice. This act is compulsory, even though we regret the situation. Therefore, we request you to kindly resign on your own, else the legal action would be taken against you.
Allen Educational Institution.