1911 please help!

Push that back in and then push in the guide rod and rotate the barrel bushing to remove the spring / guide rod if possible. There's a notch in the slide that needs to be lined up with the slide release before it will come out...double check you've done that and come back if you're still having problems.

Removing the recoil spring might make things easier but it's not necessary. I hope the slide stop isn't bent; were you able to get it back in? Like jpwilly said, the notch on the slide has to be lined up with the lump on the slide stop. You will have to hold the slide in this position while you remove the slide stop.

That is a simple pin as you probably know. I assume you have made sure the pistol is unloaded.
Find something tough plastic or wood to gently pry the stop pin. FIRST! Take the pistol by the barrel and put your index finger (weak hand) in the trigger guard. Using the strong hand pull the slide back to the first notch in the slide is directly over the pin. Trap the slide with your weak hand. Now if you have a third hand you could tap the pin from the other side. If not gently wiggle/pry the pin out. If it does not come out easily, go get the third hand and tap it out. Watch out for that recoil spring!!

It's going to take as much force to put back as it did to get it stuck (but don't use more than that). Try to tap it back in the same way you punched it out.

If that doesn't work, the end of the slide stop lever has a protrusion that engages the magazine follower (the magazine was out, right?). The protrusion has an upward hook that keeps the slide stop in place. Can you get your punch in through the ejection port and give that protrusion a couple downward taps?

You don't want to damage the frame. If it's really stuck, a gunsmith might need to cut the slide stop and replace it.

Is it just an optical illusion, or is that slide stop lever bowed?

Regarding the actual problem, it looks to me like it's hung up on the spring-loaded plunger. It probably got wedged in the gap between the thumb pad and the projection that engages the mag follower. You'll need a thin object of some kind to gently push the plunger back in and free up the slide stop. And if it really is bowed, definitely replace it. I hope that didn't happen when you were trying to use a punch to remove it. If so you'd better take a look at whatever else you might have damaged.

Regarding the actual problem, it looks to me like it's hung up on the spring-loaded plunger.

Click to expand...

That's possible, can't tell from the angle of the picture. It does look like it came out past the point where it could be hooked on the slide.

conhntr, the plunger comes out of that little tube between the slide stop and the safety. Can you see if the plunger is protruding into the notch on the end of the slide stop lever?

This is the plunger you need to push back in:

Well, I don't know how it got bowed like that but it's junk now. If you still can't get it out you'd better let a gunsmith do it, and have him replace that part with a decent tool-steel slide stop.