Floating the gears is shifting while not using the clutch.
Double clutching was mentioned earlier. To double clutch, you first let up on the throttle, then push in the clutch. Shift out of gear. Release the clutch. When engine RPMs are lower, and match the RPMs of the transmission, you push in the clutch again, shift into the next gear, and release the clutch.
The key is matching the RPMs. To shift into gear, the engine RPMs MUST match the RPMs of the transmission.
To float the gears, you do the same thing WITHOUT using the clutch.
First, let up on the throttle. This takes any pressure off the gears. Shift out of gear. When the engine RPMs are lower, and match the RPMs of the transmission, you can shift into the next gear without using the clutch.
It sounds harder than it is. You probably shift out of gear when coming to a stop without clutching anyway. This just takes it a step further.
The first few times you will probably grind 'em a bit. Don't worry, just try again. With a little practice you won't even notice that you're doing it. I found myself doing it while test driving The Muddog the day I bought him.