NOTE: Use your Service Manual for torque specs or Click Here for torque specs in the Sportsterpedia).

The factory service manuals lay out the procedure for 'stripping the motorcycle for engine repair'.
This covers the procedure for removing / installing the motor and also includes the motor mounts. However, the whole story is not in the manual.
You can induce added vibration and potential for cracks in the mounts or cases if the mounts aren't installed properly.
Below is the procedure from the manuals for removing and installing the mounts.

To remove the motor (given all other particulars have been removed as this is strictly regarding the mounts themselves);

To install the motor (Again, this is strictly regarding the mounts themselves and all other parts will need to be addressed that were removed);