how to change to Pun+?

Hi!

I was developing my first game with PUN(free).
i bought PUN+(100CCU) in the unity asset store just a minute before.
I want to apply PUN+ to my game.

How can i change the mode?
Just download and import PUN+ over PUN in the unity? or... do i have to delete PUN and then import PUN+?

Please let me know...! Thank you!