How do i Assign a player controller to a new client?

So does anybody know how i can Assign a Player Controller to a new client? Every time a new Client logs into the game it has control over player 0, and its overriding my players, witch is kinda funny. If anybody has any suggestions, or links that they could show me that would be great.

thanks

How are you currently assigning the controls? if you have a blueprint can you show a screenshot for troubleshooting?