You need to remove the top triple (the plate you see when you look at the bars... what the stock bars bolt to).
The big nut in the middle is 22mm. You'll also need to loosen the two pinch bolts that clamp the plate to the fork tubes.
You'll have to turn the front end one way or the other (don't remember which way) to clear the security tab on the ignition lock. Once you do that the plate will come right off.
You'll be looking at the top of the fork tubes. Slide the clip-ons down over the tubes, put the plate back on and there you go. Adjust and tighten everything. Go ride and then go back and tighten everything again.
DO NOT loosen the bolts that clamp the lower triple to the fork tubes or they'll fall out. This is not a disaster, but it's a hassle.
A note about lowering... that's done by loosening both the upper and lower triple and sliding the tubes up. There's more going on here than just clearance... it WILL change handling and make it sharper -- twitchier -- if you don't also lower the rear of the bike.
Clip-ons by themselves will not change the bike's handling. That's a function of steering geometry. You may FEEL a difference, though, because the ergonomics have changed.
You may want to consider rearsets or remount stock pegs with rearset adjusters too, because you're leaning forward more. Rearsets let you get your feet farther back. I find that a lot more comfortable.
I had Shinto clip-ons (adjustable for angle) mounted below the top triple but just recently moved them above and tweaked them to have a sharper downward angle. I'm liking the result... ergos are a bit better and there are no clearance issues. When they were below the triple they had to be set flatter than I like to clear the bodywork. The tradeoff is that the grips are now higher up. Ya can't have everything.