Motorcycle Repair: Front Fork oil change 1990 FLHTCU, lb increments, gravity feed

Question
Hi Mike I have a simple ??? Front forks are a little bouncy.This has air assist. Not sure of when it may have been donee Has 78000 miles on it. had 65100 miles on it when I got it oct 2005. I think it would be safe to say that it is over due on this detail for maint. I use air assist adjustments front and rear depending on load, rides great loaded two up etc. i have adjusted air by 1 lb increments up and down the scale but when running light and single i can't find any happy spot with it.Front and rear. but when i hold front brake and do bounce test. it bounces 2-3,4 times and none of my other hydo front ends ever did that. fluid should be around 11.5 wet 12.5 dry? type E fluid. I am certain if i dont remove alot of stuff i should be able to use a hanging can for fluid and a hose to fill tubes back up after i drop old fluid. if it isnt really ugly looking ( I am figuring on the worst)
But any shop hints on this project would be great.
Thanks for the great insite you have already gave me(I have read thru alot of the posts here)
Rip

Answer
You probably need to change the fork oil. There are two ways to go about it. One is drain it and then put the oil back in from the top cap. The problem is getting to the top cap. the other way is to remove the oil and suck it back it with a vaccumn pump through the drain hole. It isnt going to gravity feed
Good luck and happy riding
Mike