After doing some other work to my Colt I decided to change out my thin thumb safety to an EGW wide safety and ran into a problem.

I removed the old safety and slid my new safety in place not expecting it to seat all the way. Well after it seated I tried to flip it up and down with no luck. It will not move up to the safe position and I cannot wiggle it out of the frame.

I've removed the main spring housing and sear spring and still can't get it loose. It looks like it's getting hung up on the sear but I'm not sure.

It doesn't appear to be getting caught on the safety plunger either. It will move up just enough to get past the plunger notch on the safety.

Any ideas?

Betting it's the plunger. Been there, done that.

I agree it is the plunger spring that is holding it in.

It takes a bit of wiggling and moving around to get it out. A good way I found is to move it up and down but at the same time wiggling it. I imagine since it wasn't fitted that it's a bit tighter than usual. If it lifts just slightly you can probably put a sharp item behind it and kind of lift it ever so slightly to avoid scratching the frame.

In the future, don't put the plunger spring in to test the fitment. It shouldn't need it per se but you want to check fitment as you file off and be able to see that it goes in smoothly.

Thanks for the tip, I'll try jiggling the plunger more this evening. I am able to move the safety up past the indentation for the plunger and walk it out slightly. I've tried depressing the plunger itself and working the safety already though. The only part I can see contacting the plunger area is the very bottom edge on the safety and when it gets to that point obviously a tool won't be fit in there to depress the plunger anymore.

I just can't wrap my head around it seating so easily and then not budging lol.

That's a good thing though, isn't it? That something so small yet is capable of preventing the firearm from firing, even if the strongest man in the world tried to pull that trigger as hard as he could he would not be able to break that thin piece of metal. that also means you have more metal to work with to fit it.

Finally got it out. I'm assuming the cross pin on the safety was a little too wide.

Finally got it loose by tapping the safety cross pin with a brass punch and it just popped free.

What a pain that was.

This might help.