Motorcycle Repair: Harley front end, fork oil, triple trees

Question
I am trying to convert a narrow glide front end to a wide glide using a kit.  I need to get the top caps off the tubes, is there a trick to getting the cap off without the tube spinning in the slider?  Also must the fork oil be drained before trying to get the top cap off.  And how do I make sure that the pressure is off the inner springs while I'm doing all of this?

The bike is a 1993 Sportster XLH 1200.

Thanks

Answer
The tubes are held in by pinch bolts in the triple trees so they will not spin. All you need to do is unscrew them. The is a spring on the other side of the cap so be careful. You cannot take the pressure off the inner spring. When reinstalling them you just have to use your hand to compress them. No you dont need to drain the fork oil to take the top cap off, but since you dont know how old the fork oil is  would go ahead and drain it and replace it with fresh oil.
Good luck and happy riding
Mike