Table schema:
CREATE TABLE table_10592536_8 (date_of_vacancy VARCHAR, date_of_appointment VARCHAR, replaced_by VARCHAR)

Question: What is the date of vacancy when the date of appointment is 28 november 2007 and replaced by is alex mcleish?
SQL: SELECT date_of_vacancy FROM table_10592536_8 WHERE date_of_appointment = "28 November 2007" AND replaced_by = "Alex McLeish"