Simplify the following text for a Grade 9 native English-speaking person.
Original: Edmund RÃ 1\/4 diger Stoiber ( born 28 September 1941 ) is a German politician , former minister-president of the state of Bavaria and former chairman of the Christian Social Union ( CSU ) .
Simplified: Edmund RÃ 1\/4 diger Stoiber , German pronunciation : Ë É tmÊ nt Ë Ê tÉ '' Ê bÉ , ( born 28 September 1941 ) is a German politician . He used to be the Minister-President of the state of Bavaria and the leader of the Christian Social Union party ( CSU ) .