Motorcycle Repair: changing fork oil on 90 flhtcu, hand vacuum pump, air shocks

Question
How do you change the fork oil on a '90 flhtcu, generally? I have the service manual.  

Answer
Forget the service manual.  The easiest way is to remove the core from the air fitting at the right rear of the bike behind the saddlebag.  (Front fitting is for front air shocks).   Remove the drain screws at the back of the bottom of the fork legs and let all oil drain. Pump forks to get it all out.  Replace one drain screw, fill a measuring cup with the right amount of oil and suck it up into each leg, one at a time using a fitting screwed into the fork leg with a hose running into the cup of oil.  You connect a hand vacuum pump to the fitting at the rear and suck it all up slowly, then replace the drain screw whild keeping just enough vacuum to keep the oil from running out.  Now that you know how to do it you can take it to someone who has the tools and has done it before.