How to delete unused assets in a module

I am working on a module and have different versions of a map in it and want to delete all but one. What is the best way to do this, I didn’t see a way to do it directly in Vassal. I tried unzipping the module, removing those assets and rezipping but I ended up with an invalid module. What is the best way to do this on macOS? I have a few guesses but I figure most people know the procedures.

In the Editor: Tools menu → Remove Unused Images

I tried unzipping the module, removing those assets and rezipping but I ended up with an invalid module.

There’s an item I wrote for Tips & Tricks in the wiki on precisely this common pitfall.

Cool. Looks like an easy solution. But I wouldn’t have figured that out myself. Thanks.

I’ll look into a zip app that will allow me to direclty edit the insides of a ZIP file. I also want to replace some graphics without going through the VASSAL app.

BetterZip is my favorite for Mac.