For loop trouble?

How do I make it so during the timer loop when it hits 5 seconds the d1 and d2 trasnparency = 1 and maindoor transparency = 0?? Thanks

players = game.Players:GetPlayers()
h = Instance.new("Hint",game.Workspace)
d1= game.Workspace.d1
d2 = game.Workspace.d2
maindoor = game.Workspace.maindoor
dooropensound = game.Workspace.dooropen
warmusic = game.Workspace.warmusic

while true do
        wait(1)
            if game.Players.NumPlayers >=2 then
            wait(1)
            h.Text = "Starting the clash soon"
            wait(2)
            h.Text = "Ready to battle?"
            wait(2)
            for fivetoone = 10,1,-1 do
            h.Text = "Begins in"..fivetoone
            wait(1)
            end
            wait(1)
            for o = 1,1 do
                if maindoor.Transparency == 0 then
                maindoor.Transparency = 1
                maindoor.CanCollide = false
                d1.Transparency = 0
                d2.Transparency = 0
                dooropensound:play()
                warmusic:play()
                warmusic.Looped = true

                end
                end


            h.Text = "Go"


            for i,v in pairs(players) do
            sword = game.Lighting.Sword
            swordclone = sword:clone()
            swordclone.Parent = players.Backpack
            end

            for timer = 30,1,-1 do
                wait(1)

            h.Text = "Time left till battle ends"..timer
            end
            warmusic:stop()
            warmusic.Looped = false


        else
        h.Text = "There needs to be 2 or more players to begin the battle.."
    end
end