I made a couple sleeves with proper inside contours to capture and release the hammer spring off the pin punch used to remove the spring with the guide bar.
Chucked one end in my drill press and used a small vise to holt the other. Really solid and completely eliminates any chance to launch the spring.
Here is what i successfully used today in a parking lot.
Got a large C-clamp and made a couple crude aluminum guides. When I initially tried this, the ends started to slide off the C-clamp. You know what I mean as it happens all the time with these.