The basic principal is extremely simple, remove the dust over, insert tool, rotate it around the leg over 360 and slide out catching the debris.
Bounce the forks a couple of times, repeat the above.
If you are showing now oil on the har chrome fork leg you are good to go
or for visual leaners
doing this could potentially save you a few hundred dollars and down time from your bike
if by chance you are out on the road and you have a fork seal leak and forgot or haven't bought your tool yet, chances are you could make one easily simply by cutting some thin plastic as a single use version
Plastic insurance cards or a plastic soda bottle both work well