New Roblox Topbar Edit Transparency?

Ok so i've been looking everywhere on google to find out how to edit this stupid topbar that has completely stopped my games development because it says "Label" At the top of the screen because of my areapromt GUI And. I finally found this page:http://wiki.roblox.com/index.php?title=API:Class/PlayerGui/SetTopbarTransparency" But. I can't figure out where to put the local script? Can anyone help me please this seems so simple yet so hard. The script i tried to use is below-v

game.Players.LocalPlayer:WaitForChild('PlayerGui'):SetTopbarTransparency(0)

Thank you for reading.