1./Install ZBrush 4R6
2./Start ZBrush 4R6 and Click on Phone Activation (you ll get a Request Code)
3./Start XFORCE keygen and enter you Request Code
Generate your personal Activation Code
4./Click on Enter Activation Code and enter the one you generated.
5./That's it Enjoy this master piece ..
NB:OSX keygen to be executed on a windows machine