1. If you have the Lite version still installed you need to remove it, i.e de-activate and delete it from your site. You might lose some auction information.
Once you have done that then re-activate the Pro version. Let me know any other issues you face after this.
Yes, it's a .zip file. That's the only format we have in our download area when you click on the "Download" button from your Weborithm Products member area.