When I did them and I did manay many many of them Drain and replace with about 400cc of ATF (There is no damping the oil is purely lubrication of teh Teflon inners
"BUT"
The little 3mm allen headed screw at the very top .... Make sure the O ring is on it !
Normally when I am doing it, as I draw the tube back up to the top yoke. I refit it and snug it up about 2 and a half inches below the top yoke To compensate for the extended suspension
Most people will fit them when the bike is on the centre stand and the back wheel always hits the deck and the front extends an extra 3 inches