when changing the needle, leak jet or pilot jet, you do not have to pull the carb completely off the bike but you need to loosen it enough to be able to access the bowl screws and stuff. I loosen mine enough so i can twist it out of the clamps - you want to be able to see what you're doing. Having a second person and a flashlight is also pretty handy, but not necessary. The main jet is a little easier, it's located underneath the carb (you will probably want to loosen the clamps so you can rotate the carb just a bit) but all you would need is, i think it' s 17 mm wrench, unloosen that and the main jet is located right up inside.
06 Honda 450ER
Rossier full
HotCams Stage 2
EHS lid -- K&N
Pro-Armor
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06 Honda 250EX
HMF sport full
K&N -- Fly bars