Hi Zetnus - that only works when the game hasn't started. Currently there isn't an official way for a host to drop a player, other than manipulating the timer when it is that players turn.
However - if you tell me the game number and the player, I can remove that player from the game for you.

Thank you for your quick reply. In the end I managed to drop the player by temporarily lowering the skip limit. (This person had missed 3 of the first 4 turns.)