Install a 6mm screw through the lower fork drain access threaded hole, gently wind it in till the screw nudges the inner alloy tube , carefully tighten up ,then remove the retaining Allen bolt from bottom of fork leg.If no luck, tighten the screw a fraction.The whole spring and damping assembly should be able to be withdrawn from the top.
If the spring is out a long flat blade screwdriver will be able to engage the damper , so as the Allen bolt can be undone.
Hope this helps.