Stuck fork retaining bolt

I'm trying to change the forks seals on a 1979 Suzuki TS250. So I crack the retaining bolts that go through the bottom of the outer leg into the plunger. I'm unscrewing them, thinking what a talented tinkerer I am. Boy, this is going to be easy. Life punishes the smug. So I turn and I turn on the socket head bolt that holds the plunger to the bottom of the leg and I notice that even though it feels real loose it just keeps turning. And turning. The screw came partly out and now the cylinder is turning with the bolt and not getting any looser. So I figure I'll get back to this one and I go to the other leg. Same thing. About this time, a couple hours into a 30-minute project, I start thinking about how to keep the cylinder from turning so I can get the screw out. I briefly consider - in all seriousness - flattening the lower leg with my sledgehammer. That will keep that sucker still. I also consider filling the leg with cement and letting it set. It occurs to me, though, that either of these methods may compromise the forks ability to absorb shock once remounted. Anybody faced this before? Any ideas how to keep the cylinder from turning so I can get these stupid bolts out? Thanks and Merry Christmas. Pat

Thanks, Dave. I'll have to give that a try. The bolt is loose enough for oil to drip out, but for some reason it stopped turning about halfway out. I've tried pulling on the inner tueb to create drag. Nothing. I tried pushing on the inner tube to try to keep the cylinder still. No luck. I've already tried my impact wrench. It just spins the bolt. I also put the spring back in. I felt some resistance after that, but not enough to get the bolt to turn out. I even put in a spring I had from another of my bikes that was longer and it provided more resistance, but that sucker still wouldn't come free. I tried jamming a broomstick down the tube, but it couldn't get a grip on anything. I tried removing the fork oil drain screw at the bottom of the leg and jamming a small screwdriver into the hole to try to hold the plunger still, but it found nothing to grip. I've got some old tubing, including and old vacuum. Now that I know what kind of tool to try to fabricate I'll give it a try. Here's hoping I get lucky.

A ratching tiedown and air impact wrench. Bingo. Now to pry out some 26-year-old seals. Once again, the friendly folks on this board gave me the answer. Thanks guys.

Merry Christmas and I hope all your teams win their bowl games.