removing the fuel tank
Time needed: About a half-hour; less if you're not a big slob like me, and don't spill gas all over yourself.
Note: I really don't need to tell you people that fuel tanks contain gasoline, which is flammable, right? Make sure you've got a fire extinguisher handy just in case. Also, y'know, don't smoke anywhere near your garage.
Now go find a friend. We'll wait. OK? Have your friend or loved one tilt the tank back and hold it there, while you go get a 10mm socket, extension, hose clamp pliers (or needlenosed pliers), and some shop rags. Look under the tank towards the rear -- you'll see the fuel pump with a nice little yin-yang looking piece on it that says "on/off". Stick your 10mm socket on the boltish looking thing that's sticking out (helpfully, it's not octagonal, but the 10mm socket will still fit) and turn. It's really impossible to tell just from looking at the yin-yang when the fuel is on versus off, but assuming it was on to begin with, just keep turning until it's turned 180 degrees and won't turn any more. Safe to say it's off now. Why they couldn't have just put an arrow on there or something is anyone's guess.
Bribe your friend with a beer to keep holding the tank up. On the sides of the fuel pump that you just mucked with, you'll see two large grey fuel lines (one on each side). Pull 'em out, being careful of any gas that had been in the hoses (hence the shop rags mentioned earlier).
Once that's under control, look at the underside of the tank, and you'll see two drainer hoses leading directly up into the tank. Pull each of them out. They have different diameters, so you probably won't mistake them when it comes time to replace the tank.
OK, almost done. On the backside of the fuel pump is a small diameter hose. This is the vacuum line to the rear cylinder. It needs to come off, too.
You're done with the hoses. Look behind the tank, under the seat, and you'll see a big plastic sleeve containing a cluster of electrical connections. One of these connections can be traced back to the underside of the fuel tank -- it's the fuel sensor, and you'll need to disconnect it.
Now you can take the tank away from your poor friend, or, heck, make them carry it away themselves. Storing it right-side up is easiest if it's a temporary thing. Just make sure that you've got rags or cloths underneath it so the paint doesn't chip. Obviously, make sure that you don't care if the aforementioned rags get gasoline on them, and, for the love of god, don't smoke around them.
If you're going to be storing the tank off of the bike for a prolonged period of time, you can store it upside-down if you prefer, but be careful. I've found that if the tank tips forward while upside-down, gas will seep out of the smaller drain nipple, run down the length of the tank, and collect in the bowl-like underside of the tank. Since it picks up dirt from the foam glued to the underside of the tank, it will turn disgusting colors. If left sitting for a while, it will also start to smell heavily of gasoline (not terribly surprisingly). This may, hypothetically, cause your neighbors to break into your garage while you're gone over Christmas and try to figure out, hypothetically, where that reeking smell of hypothetical gas is coming from. This is hypothetically very embarrassing. Plug up the drain nipples, or prop up the tank so that gas doesn't leak.