Changing players character/controlling other players?

How would I do this? I tried looking through person299's admin commands and copying that, but sadly it doesnt work. you just loose character.

Heres what I have got (no errors, i can control my character but camera becomes unlinked)

function respawn(player)
if player ~= 0 then
local ack2 = Instance.new("Model")
ack2.Parent = game.Workspace
local ack4 = Instance.new("Part")
ack4.Transparency = 1
ack4.CanCollide = false
ack4.Anchored = true
ack4.Name = "Torso"
ack4.Position = Vector3.new(10000,10000,10000)
ack4.Parent = ack2
local ack3 = Instance.new("Humanoid")
ack3.Torso = ack4
ack3.Parent = ack2
player.Character = ack2
wait()
player:LoadCharacter() 
end 
end 



Player = Game.Players.LocalPlayer
Mouse = Game.Players.LocalPlayer:GetMouse()

Mouse.Button1Down:connect(function()
    if Mouse.Target ~= nil then
    print("recieved "..Mouse.Target.Name)
    if Mouse.Target.Parent:FindFirstChild("Humanoid") then
    local clickedplayer = Game.Players:GetPlayerFromCharacter(Mouse.Target.Parent)
    Game.Players.LocalPlayer.CharacterAppearance = "http://www.roblox.com/Asset/CharacterFetch.ashx?userId="..clickedplayer.userId.."&placeId=0"
    cloned = script.TimerGui:Clone()
    cloned.Parent = Player.PlayerGui
    respawn(Player)
    for i = 1,120 do
        cloned.Frame.TextLabel.Text = "Disguise time left:"..i.."s"
        i = i - 1
        wait(1)
    end
    cloned:Destroy()

    end
    end
end)

Thanks