How to change a players body and head when they enter the game?

I am making a game that I need the players to morph into these "armor suits" (they must not be able to take them off, as they need to have them on the whole time). I have the asset I want to the players to morph to when they join. How do I do this? Is there a tutorial that shows this? (note that I am not very good at scripting).