I started a private tournament and one player joined but hasn't taken any turns.  Is there a way I can remove him from the tournament, or does he have to remove himself?  I can wait for the boot timer to remove him from an individual game, but how does he get removed from the entire tournament?

He will eventually be auto-booted. I think it takes 2 games of booting in a tourney to get booted from it - not 100% on that though.  In any event, the system won't let a tourney host boot a player.

so - 2 turns of skipping in a game to get one boot...or if the player never joined the game, that's one boot. Ditto for the 2nd boot.

Ok, thanks. I'll wait for the auto-boot to do its thing.

How can he take himself out? Would he have to click Surrender for every one of his games?

Yeah, a player always has the option to surrender out of a tourney from the tourney page. There is a ‘quit tourney’ button.