To convert an ICAO licence to an EASA one, you will need to re-sit your CPL and ME/IR skill tests with a minimum of hours flying at a European flight school. Depending on where you do this in Europe, it can cost you from £4,000 to £8,000 for the conversion - Poland, Lituania or the Eastern European countries will cost less. These are just ballpark figures, I haven't been to each school's site to find out the exact amount. Plus get your EASA Class 1 medical. Don't do your ATPL in SA, else you will have to re-sit all 14 exams for the EASA ATPL.