how can I to get rid of unwanted players in a tournament

I started a swiss chess tornament as an administrator in my team. Mode is standard time (90 min) for 7 rounds, one every week. In my team are also kids, who do not read the tournament description and do not really want to play, but they click on "participate". As an administrator I am not able to kick them out. I also cannot tell them to do so, because their parents prevented chats for them. What can I do? Set a password in order to prevent new registrations?

you can put a passcode and tell the people that you want to join the passcode

Or you can kick them out of the team and let them back in after the tournament.
:D

You can't actually add the person he needs to join by himself

@RCW5 : Does that also work, when the tornament has already started?

Nope