I used to try (emphasis on the try) to replace brass sleeves. Occasionally they will slide right out. Most of the time they range from difficult to get out to impossible to remove. It's just not worth the effort and the possibility of destroying a coil. Unless that brass sleeve is scratched or damaged, you probably won't see any difference anyway.

I've replaced damaged coil sleeves, both nylon and brass, because I had no choice, but I don't even replace nylon sleeves anymore unless I see signs of wear or damage. I think people just get stuck on the idea of: "Well their only 50 cents, I'll just replace them while I've got this apart". That's fine if you can push it out with little effort, but that's usually not the case with most brass sleeves.

Just one more thing that follows my, if it ain't broke don't fix it policy