Please keep The Events Calendar (the free version active) as Events Calendar PRO builds on top of this, it doesn’t replace it.
Grab a copy of the .zip file for PRO from the downloads page and simply upload it to your WordPress site via the Plugins → Add New → Upload admin screen.
This thread’s not seen much activity for the last couple of weeks so I’ll go ahead and close it. Of course if you still need help with this or any other issue please don’t hesitate to create a new thread (or threads) and one of the team will be only too happy to help. Thanks!