yoyudax: you can resign your games in the tournament, but the tournament wont be finished before all games of all players in the tournament are finished

so you can resign your games, but will still have to wait for the others to finish

but: when your games in a tournament are finished, and you have no chance to continue to the next round, then you can ask fencer, nicely, if he can remove you from the tournament so you can join a new one. he is the only one who can do it .. so be gentle :)