clamp the fork in a vise. On the bottom of the fork is a 6mm allen pull it.
With a socket un screw top nut. Its under pressure and can fly off. So go slow. Once top nut is off let fork drain. In your mode there is just a spring in side. Don't do any thing ells to fork just let it drain. If the seals didn't leak before they should not leak now.
Hard part put spring in and top cap nut just get it started. Now take fork and turn it up side down. Put in 6mm allen and brass washer. Get it tight.
Now turn fork over un do cap nut pour in oil put cap nut on and tighten it.
Just so you know that bushing thats on the bottom of the fork tube takes about a 100 thousand miles to wear out.
Please add your state and model of bike you have. Click user CP @ top of page and then far left click edit signature. Thanks