Turn fuel petcock to the "Off" position.

Set fuel catch system up next to the left carb...in this example a 5 gallon fuel container with a long funnel dropped into the spout bung.

Disconnect the fuel line to the left carb...

...and place the end of the fuel line into the funnel.

Put the petcock into the "Reserve" position...fuel should now flow into the container.

If you want to be anal you can unscrew the fuel tank filler cap so the gas will flow faster...maybe.

When the fuel has finished draining, remove...

...the right fuel line to the right carb.

Next, use a pair of pliers or a screw driver blade to remove one end of the fuel cross-over line...

...careful, as there will be residual fuel that will drain out. After tank removal, remove and inspect this line for crud.

Gently feed the fuel lines out side of the frame so they will not hang up upon removing the tank.

Use a 17mm wrench and 14mm socket and ratchet to remove the forward seat retaining bolt...

...here is an overhead view...

...and here is the bolt removed. Put the nut and washer back on and place the bolt in a parts box so it doesn't walk off.

Now the seat can be tilted back so the tank has enough room to clear it. Easier than removing the entire seat assembly.

At the forward end of the gas tank are two 12 mm retaining bolts, one on each side of the tank. Use a 12 mm socket and extension...

...to remove both of these. Place the bolts, washers and grommets in a parts box.

To remove the tank just lift the rear up, the tank is secured by two clips on the tank which fit over two rubber bumpers; a tug will pop it free. Then just slide the tank back to clear the handle bars...

...and you are done. Set the tank on something soft to prevent damage to the paint.

This is a good time to change out fuel lines, clean the petcock and flush the tank.

Installation is the reverse steps.