I just replaced mine last weekend.
Simply remove the tank from the bike, drain the fuel, flip it over and unbolt the fuel pump bolts, and then comes the fun part.
The fuel pump is such a tight fit you will need to caress it to get it out. BE CAREFUL and take your time. There is a small piece of plastic that will be difficult to get past, so be gentle.
After that, make sure you use a NEW fuel pump O-ring, and slide the pump into the new tank. Put some loc-tite on the bolts and torque them down to spec. (87 inch-lbs) Reinstall the tank on the bike.
Next, unbolt the (3) screws that hold the gas cap on the old tank. This is easiest to reinstall with the new tank already mounted on the bike. Be careful not to loose the little rubber grommet that seals the overflow tube underneath!
Even though there are (5) screws in the gas cap, only (3) of them actually bolt it to the tank. The other (2) are just cosmetic, and are very short. Carefully put the rubber grommet in the correct spot on the new tank and then lay the gas cap over it. Loc-tite the bolts and tighten them down just snug. Be sure you align the cap by closing it after snugging the bolts down before you tighten them permanently.
Refill with gas and fire her up! Check for leaks.
