Step 1. Get the bike up in the air and remove the back wheel, hugger and belt guards. Make sure you have plenty of room to move around in there.
Step 2. Put a jack (preferably with wheels) under the transmission to support its weight when you remove the two big allen bolts that hold the isolators to the swingarm block. These are 1/2" head allens. If you don't have an allen socket of that size, Lafayette has a cheap substitute: buy a 2" long by 1/2" "coupler nut" and stick it into a (six point) 1/2" socket. Voila! An Allen substitute! So, with the jack supporting the trans, remove the two allen bolts.
Step 3. Assemble the tool shown below. It's made from about six inches of 3/8" diameter threaded rod, three nuts, a cut-in-half 9/16" box wrench, and two pieces of stout pipe that slip over the threaded rod. I actually used a pair of Harley Sportster turn signal stalks for this.
When assembled, the tool looks like this:
Step 4. Slither up under the rear end of the bike, taking a 1/2" and 9/16" wrench and the tool you just fabricated with you. Remove the 9/16" bolt that fastens the turnbuckle to the swingarm carrier. Then remove the 1/2" bolt that holds the ground strap to the swingarm carrier. You'll find the hole goes all the way through the boss on the swingarm carrier, and it's tapped all the way through. So re-install the bolt from the left side, so that about 1/4" of it sticks out the right side of the boss. This provides a pin for the left end of the special tool to align on.
Step 5. Brace the cut-down 9/16" wrench part of the tool against the top of the swingarm carrier, and turn the nuts (fingers should be adequate) until the other end of the tool is pressed up firmly against the inside of the frame just above the right isolator. See the picture below:
Step 6. Now turn the nuts to spread the tool out and shift the engine/trans/swingarm carrier to the left. This is not actually spreading the frame; it's compressing the left isolator. You will need to apply a lot of torque, which is why I put a long lever (a jack handle, actually) on the wrench. The cut-down wrench that's a part of the tool keeps the threaded rod from turning. Keep turning the wrench and extending the tool until you can pop out the right isolator, as seen below:
Step 7. Turn the nuts on the tool the other way (the cut-down box wrench part will flip around and brace itself against the swingarm), until you can remove the tool.
Step 8. Give the swingarm a yank to the right, and the left isolator will drop out.
Step 9. Slip the new left isolator into place. Make sure it's aligned properly (see your Buell service manual). Reinstall the special tool, and repeat step 5 until you've compressed the (new) left isolator enough to slip the new right isolator into place. Make sure the belt's in the right place before you install the new isolator; the last thing you want to do is button up the job and discover the belt's dropped out! (Matter of fact, given that you've got the isolators off, inspect the belt closely--if it's even remotely near needing replacement, slip in a new one now. You'll thank yourself later!)
Step 10. Repeat step 7 and remove the special tool. You'll probably find the threads on the threaded rod are a bit monged up by now, so you may need an extra wrench to keep the rod from turning in strange ways.
Step 11. CAREFULLY start the allen bolts through the isolators and into the swingarm pivot. This can be tricky. You may have to fiddle with the jack a bit to align things properly. Be patient; you don't want to mess up the threads. The last time I did this, I found that the passage of time (and previous removal/replacement of the bolts when I did a belt replacement two years ago) had messed the threads up slightly. A quick cleanup with a 1/2" SAE fine tap solved the problem, and everything went together nicely. Don't forget the Loctite! Once both bolts are started, and you've again checked that the isolators are in the correct alignment, tighten the piss out of the bolts, to whatever monstrous amount of torque the manual specifies (about four grunts, if I recall correctly).
Step 12. Re-install the turnbuckle to the swingarm carrier. You may need to give the swingarm a little shove one way or the other to get things lined up. Re-install the ground strap (remember it bolts to the right side of the boss). Re-install belt guards, hugger, and back wheel. Lower the bike, give everything one last check, and you're ready to go.