Install PD6 Switch to Mac over PD6

to keep my story short, seeking advise on the need or process in whether do i need to install a newly bought PD 6 (Switch to Mac) on my MacBook which PD 6 was already been installed. Reason is the installed PD 6 belongs to my buddy and hence i do not have the product key. However, I bought the PD 6 (Switch to MAc version though) and whether do I need to delete the initial PD6, currently I have already several applications under the VM. Thank you