it's in the service manual... you DO have a manual, right??
ok, take off brake caliper(s), remove front wheel, remove fender, remove forks from bike, drain fork oil, take out springs through top cap, remove clip for seal, remove damper tube bolt from bottom of fork legs, pull apart (NOT force apart). reverse to reassemble
The genuine Harley-Davidson Service Manual for your specific model and year bike has the procedure. You will save yourself a LOT of problems if you have the proper Service Manual.
The bolt (metric cap screw) at the bottom of the slider is easier to remove with air tools. The bolt is NOT in there very tight, but will just "spin" if you try to remove it with hand tools. An air tool will take advantage of the damper tube's inertia to break the bolt free. You can do it with hand tools but you need to fashion yourself a tool that reaches down into slider and keeps the damper tube from turning.