How to Access a player's GUI via a normal script?

I am trying to make a button that, upon being clicked, will subtract GUI currency. However I can't say "game.Players.LocalPlayer.etc..." because "localPlayer" does not work in a normal script. Here is the code I have now:

script.Parent.MouseClick:Connect(function(plr)
	if game.Workspace.Data.Buildingname.Value == ("ArcherHut") then
		game.Workspace.ArcherHut:SetPrimaryPartCFrame(CFrame.new(-731.5, 6.5, -2676.5)) -- sets moedel cframe.
		wait(0.1)
		game.Players.LocalPlayer.PlayerGui.Money.TextLabel.Number.Value = game.Players.LocalPlayer.PlayerGui.Money.TextLabel.Number.Value - 50
	end
end)

The server cannot access the descendants of a PlayerGui through normal means of FilteringEnabled. Any edits done to any GUI object in the PlayerGui must be done from a local script.

Looking at your code, you can easily convert a ClickDetector event to a GUIButton event; you just need to specify what mouse button is being pressed. If necessary, you can use a RemoteEvent to place the hut on the server so that everyone can see the placement.