[lugerholsterrepair]

Removing the hold open is one thing. Removing and replacing the flat spring is another. Once you have the hold open out you must push the old/weak/broken spring out right to left with a VERY small drift. I usually use a small finish nail I flattened the end on. Then take your new spring and line it up..see if it will start enough to hang on then either press it in with smooth faced pliers or set it on a steel block and gently tap tap..
If you can find an original you have confidence in it's going to be much better. Repro's I have never had much luck with.

Once you have installed the spring..getting it back into the pistol is a tad tricky..push the end of the flat spring into/onto the well ramp to start noticing that it must be depressed some to engage the hook into the round catch below while shoving forward. Just look at it closely before attempting insertion. It's pretty logical really. It helps to have the pistol stabilized so you can use both hands.