I have only gone through a set of K1 carbs, and those wrenched out with an 8 or 7mm wrench. I think they're called emulsion tubes...should have horizontal holes in them. I've been through lots of CV carbs that have the jet-needles simply pressed in...well...they actually fall out once the emulsion tube if removed. Sometimes you have to pry them out from the carb-throat area with something soft...like a rubberized set of pliers handles. Either way, replacing them made a hell of a difference on my old bike.
Good luck