There are a few ways in which to become a safari guide in South Africa. If you already live over there then you may be able to speak to one of the many lodges and ask about becoming an apprentice. If you want to give yourself the best possibility of landing the job then you may want to consider doing a course to become a professional field guide who is FGASA- and CATHSSETA-qualified. These courses normally take about 12 months to complete and although often there is no requirement for experience or previous qualifications, you will need to be fit enough to walk at least 2km and possibly will also need to have a driving license.
It has got to be one of the jobs people dream about, getting to spend months out in Africa up close to wildlife in its natural habitat, learning all about the animals and how to keep them safe whilst at the same time getting paid for it. Many students chose to work in a safari lodge during a gap year as it can offer them an experience like no other job can.
It you are interested why not contact a few of the lodges and find out what you will need to go and work for them?