Andrew Birkett's nobugs.org
So, rather than brute force, I suggest doing the following. Don’t fully disassemble the fork leg; just take dust seal, spring clip and the main spring out, extend the fork fully and fill up to the top with oil. Put the cap back on, and find some way of compressing the fork – I’ve used a big hammer before (with a bit of wood to cushion the blow), and others have used long clamps, or even wedged the fork between car and a wall and used a bottle jack to compress it. Either way, when the pressure builds up, the weakest point is going to be the fork seal, which will pop up in a messy spray of oil .. but, hey, at least it is out. In the photo you can see the fork leg on the left, the damper rod seat and the damper rod in the middle, and the stanchion (with both bushes) on the right. The damper rod is bolted to the base of the fork leg. Sometimes when you are undoing the bolt, the damper rod starts to spin. I’ve found that a wooden broom handle pushed against the top of the damper rod stops it spinning pretty well, and allows you to undo the bolt completely.