How would I make a player spawn with a morph with the Player Added function?

I'm not requesting a script. I tried to think of something but I don't even know where to start, this is what I got so far.

game.Players.PlayerAdded:connect(function(player)
     	while not player.Character do wait() end
	local Ch=player.Character
        Ch["Torso"].Transparency=1
	Ch["Head"].Transparency=1
	Ch["Left Arm"].Transparency=1
	Ch["Right Arm"].Transparency=1
	Ch["Left Leg"].Transparency=1
	Ch["Right Leg"].Transparency=1
end)

game.Players.PlayerAdded:connect(function(plyr)
      game.ServerScriptService.script:GetChildren("Arm1") -- Arm1 is a model and I want this model to be the player's Arm when he spawns But idk how to make it!
end

I want the player's original body to be transparent and the morph to be on the body, but Idk how to put the morph on. Help? I'm stuck! Tell me everything I did wrong please!

You need to use welds.