Not something you can do yourself with just a cable and a bit of software you got from the internet, those days are long since gone!
You can either pay for the unlock code using a unlocking service, this is neither fast or cheap! Cost around £25 = R400
Take it or post it to someone with the required hardware like amalou has offered you. Cost = ???
Invest in a Turbo SIM that sits between your own SIM and the phone. This has the downside of having to trim the corner off your SIM card! But on the plus side, your SIM should work in any other network locked phone. Cost around R200 or less - I charge R180 for these.