For an IMC instructors rating you need 50 hours IFR, IMC rating and complete a course with an FIC instructor, 5 hours flying and 35 hours ground,realistically it will usually take more than 5 hours cos of all the course teaching, e.g. G.H.full and ltd. panel, NDB hold, ILS, RADAR APPROACH, VOR tracking, HOLDING procedures, you also need to pass the flight test. The night is much easier as all you need is a night rating, 10hours night and 1 hour (minimum) night training and 3 hours ground from an FIC instructor and no test. Detail are in JAR/OPS section 11 and in appropriate AIC,s