can anyone explain it?

are you sure you need to adjust the float hight? did you check the float hight?

OK floats are inside the float bowls. Carbs have to come off. Then unscrew the float bowls and adjust them. The float level checks can be made when they are still in the bike. U tube method. Use clear plastic hose that fits tight on the drain spigot of the floats. Then hold it up to carb body like a U and unscrew the drain screw. Then put it in prime. Mark the level of fuel in the u tube and repeat with other carb. Up to the top of the bowl and no more is stock level and works fine for most cases.
Air screws are under a brass cap on the under side of the carb, towards the front. They can be unscrewed for richer and screwed in for leaner. Remove the brass cap by drilling it out, then use a small screw driver. I use a little screwdriver bit to fiddle with them when they still on the bike. Works great.
Cool.
Srinath.

I need to drill them out I just rejetted and I don't understand how this works.  Is there any pictures that someone has on this.  I see the brass deal, but what kind of drill bit do I use?  Also I replaced the needle that was supplied in the rejet kit instead of using the washer.  How do I know how to adjust the needles?  Is there some sort of guide?  I have a 2001 I put in 127.5 main jets and 22.5 pilots.  My bike was running rough I think it's too rich now, and I am guessing I need to take off the carbs again just the needle level and drill those screws, but I would love to see pictures first if anyone has them of this process.  At least I know my way around the carbs now.
Thanks for any help.

http://electrovw.tripod.com/welcome/id17.html

http://www.angelfire.com/mt2/mikesgs500/rejetting/


These should show you how.

These did help me some what but my bike is still not running right.  There is nowhere that explains how to properly adjust the needle of the factory pro jet kit.  It seems that my bike is still sputtering and I am having a really hard time getting the mixture right.  Currently I have it set to 2.5 turns.  I wish someone could help me......