I think the bike sat outside for a long time by the previous owner. There is rust around where the fork meets the frame. It squeeks on turns, so the ball bearings need grease. I would like to rebuild that area, which means removing the stem and the fork.

The bolt that causes the stem to clamp down is easily loosened. When it’s out by 5mm or so, I can easily tap it down with a hammer. So the wedge at the bottom can move freely. But no matter how loose that is, the stem is one with the fork. I have sprayed a good amount of wd-40 and it has had plenty of time to soak.

I have tried removing the wheel, then having the fork straddle someting strong, and tried forcing the handlebars to twist. That just caused the fork to spread. I actually had to correct that by clamping the fork back in place so it could slip onto the axle again.

With the wheel off, I tried banging on a steel rod from the bottom side. I did not want to damage the wedge so I limited the amount of shock I was willing to deliver.

What do pros do in this situation?