And in a local script in StaterPlayerScripts you can do the following:
local Part = --the path to the instance that the gui should be parented to
local Gui = -- the path to the surface gui (make sure it's not in workspace by default but in replicated storage)
local Event = --the path to the "StartCount" event that should be in replicated storage
Gui.Parent = Part
Gui:WaitForChild("PlayButton").MouseButton1Click:Connect(function()
Event:FireServer()
end)
And that should do the trick!
Tell me if you experienced any issues