Yeah that pic is the first I have seen disassembled in THAT order LOL.
As always, and you will no doubt have other areas on that bike needing the same technique...
Lube, twist, Use a chunk of aluminum or brass to protect bolt ends and threads before hammering. Tap/hammer. As soon as you get movement, STOP, lube again, tap it BACK IN, lube then tap back out repeat. This will greatly reduce galling and metal tearing as the corrosion can wad up and tear the crap out of both parts.
Lets see some more pics, looks like a serious "back from the dead" project!
Getting the fork leg off the axle will probably be the easy part, the axle is likely frozen in the bearings that will be the hard part because you can't "spin the axle in the bearings they will just turn with the axle. I thnk with the fork leg free and the disk removed. several aps of lube and heat before the serious beating starts may help. Good place to use a harbor freight heat gun, heat both ends of that axle a few times. wear gloves. In case it's not obvious, you will need to replace those wheel bearings on this one.