hsmp switch for current wp dependent

Hi there im a workpermit dependent and from south africa.
my partner is from australia.

i would like to get a hsmp visa, as i qualify for it, and then let my partner be my dependent.

I know that I have to go to South Africa to apply for the hsmp.

My question is:
How long does it take in SA to get the visa and
what is the procedure for my partner to be my hsmp dependent?

Thanx