Ah, I replaced my stock with a Drummer and had to do nothing of the sorts.
What exhaust system are you replacing the stock one with?
Just picked this off the "Drummer" site:
These instructions apply to all Buell XB12 models.
For XB9 models start at step #4.
1. Remove the Air box cover by removing the 4 T27 torx screws that hold it in place. Don’t lose the screws and plastic washers.
2. Loosen the lock nuts on the mechanical muffler valve cable and disconnect it from the servo motor. Leave the servomotor in place with its electrical wires connected.
3. Carefully work the mechanical cable past the engine to free it completely. You will have to cut some wire ties and then replace them later.
4. Remove the chin fairing by removing the 7 torx screws that hold it in place. Don't loose the plastic washers.
5. Loosen the rear axle pinch bolt on the underside of the swingarm.
6. Using the rear axle removal tool from the kit unscrew the rear axle 20 full turns. This loosens the drive belt tension.
7. Remove the front belt guard by removing the 3 torx screws that hold it in place. Don't loose the plastic washers.
8. Unscrew the 2 nuts that retain the belt tensioner and pull the tensioner off of its studs. The studs are a close fit on the holes in the tensioner so be sure to pull off in a straight even manner. Don't try to pry it off. If it sticks then push it back on all the way and try again to pull it off straight.
9. Loosen the torcon clamp on the muffler's inlet.
10. Loosen and remove the front band clamp and the two rear band clamps that hold the muffler to the engine.
11. Work the muffler off of the header by twisting slightly and you are done.
http://www.kdfab.com/mufflerremoval.htm
This is exactly what I did when I replaced my stock rig.
Never touched the oil line.
