Local Currency Changeover - Implications

Hi,

A company code has the local currency now as USD but it wants to change the local currency to South African Rand.

What are the steps for making this currency changeover from USD to SA Rand?

What are the repercussions/implications if the local currency is changed?

What are the preparations required prior to local currency changeover?

Have any of you worked in such a scenario? What the pit-falls to watch for?

Any help in this matter is greatly appreciated.

Thanks.