Hello
The telkom Homeunlimited package (if that is what you are on) is the same price be it ADSL or Fiber, you would need to contact telkom and tell them that you are moving and want to switch to the fiber package.
If you do not need a voice line I would take this as an opportunity to cancel with telkom and signup with a ISP such as cool ideas or supersonic. They offer better performance, pricing and support.
If you choose another ISP other than ones mentioned be sure to ask about fair usage policy, Webafrica, Afrihost, Mweb, Axxess all have limits that when you reach them your performance is going to drop, telkom has one as well but its very high so I doubt many people reach it.
Regardless of what avenue you choose to do an install of some sort will be needed.