To kick someone from your private server in Roblox, first log in to your Roblox account. Go to the game where your private server is located. Click the three dots at the top left corner of the game window to access the server settings.
Next, navigate to the player list within the server settings. Find the player you wish to kick and click on their name. You will see an option to remove or kick them from the server. Click that option.
Confirm the removal by clicking the confirmation button. This will ensure the player is kicked from your private server immediately.
If you want to prevent the player from rejoining, you can block them. Blocking a player will immediately remove them from your server and add them to your block list. You need to be the owner or have the necessary permissions to manage players and kick someone from your private server.