Local Player    = game.Players.LocalPlayer
Local Character = Player.Character
Local Shirt     = Character:FindFirstChild("Shirt") or
Instance.new("Shirt", Character)-- if its in character then get shirt else make a new one
Local Pants     = Character:FindFirstChild("Pants") or
Instance.new("Pants", Character)

local shirtId   = 0 -- put the shirt id here
local pantsID   = 0 -- put the pants id here

Shirt.ShirtTemplate = "rbxassetid://"..shirtId -- set the shirt
Pants.PantsTemplate = "rbxassetid://"..pantsId -- set the pants