Once you have the fork dissasembled down to only the inner chamber you will be working with what is in the
red box less the spring.
1st. I usually put the inner chamber in a vice on the squared off portion to help me remove the assembly
(#1 in image) from the inner chamber. To remove this you will loosen it all the way and the carefully pry it up little by little with a flat blade screw driver. Once you get your fingers on it work it out slowly so you don’t damage bushings or seals.
2nd Once you have done that take it out of the vice. Flip it over to drain fluid and work the damper rod
(#2 in image) in and out to pump the fluid out.
3rd I put it back in the vice…fill with recommended oil level. Get all air bubbles out…they usually rest on the side and you can pop them or swish the fluid to remove bubbles.
4th slowly work the inner assembly
(#1 in image) back into the inner chamber. Gentle. Once that is in and tight. Slowly work the damper rod
(#2 in image) little by little by compressing it a little at a time. Note: when you compress it …it should come back out on its own. So work it little by little building up to doing a final complete compression of the rod. A little fluid may come out of the seep holes towards the top of the tube. Be sure the rod pushes itself out. If it doesn’t you probably have air in the system or a bad seal or bushing.
if the rod isn't coming out on its own then you can remove the fluid and and give it another go. basically start the process over again.