How do I replace players arm?

I want to replace the players arm with a completely new arm containing 4 union pieces ( the arm will be fully functional ) how do I do this?

removes players "Right Arm" and replaces with a new arm. or edits the "Right Arm" ? so the player can have a custom arm?

You could either make your right arm transparent and cancollide = true. Then weld your new arm containing 4 union pieces to the position where you want it.

First, StarterPlayer has the unique ability to professionally and creatively edit the player's appearance. Read more on the wiki: http://wiki.roblox.com/index.php?title=API:Class/StarterPlayer

1. Start a solo game with your character in it (F5).

2. Find the correct body scripts inside of your character's models.

3. Now, you can copy it/them inside the StarterPlayer folder, inside StarterCharacterScripts.

4. Here you can edit them, for example delete the arm in the model and replace it with a union of the same name (eg. Right Arm).