Cone error works the same on the northern and southern hemisphere
You don't need Polaris, or even a polar-aligned mount. Just swing around RA so that the Dec axis is horizontal (with the scope on one side of the mount and the counterweights on the other), go up and down in Dec a bit to find and centre a star (or far away object) in the eyepiece, swing around the RA axis so that scope and weights swap places and see whether your object is still in the centre.
By nudging the end of scope left or right to get the object closer to the centre you can figure out where the shim needs to go.
Cheers
Steffen.