/SLASHPLAY
How to kick a player in GMod
Type kick "Player Name" in the server console to remove that player at once. They can rejoin straight away.
kick
Removes a player from the server by name; they can rejoin right away.
kick <name> Examples
kick "Player Name" Kick a player by name.
Arguments
nameRequired- Player name, in quotes if it has spaces.
What it does
Removes the player immediately; they can rejoin straight away. If the name has spaces, put it in quotes. kickid is safer when names are similar or contain odd characters.
The game's own description: Kick a player by name.
Run it on your server
On a SLASHPLAY server, type it in the Console tab of the server page; the reply shows right under it. A value set there lasts until the server restarts. To keep it, add the line to garrysmod/cfg/server.cfg. New to this? Start a GMod server first.
Your own
GMod server.
From $0.03 an hour, only while it runs. New accounts get 6 free tokens.