if the EZ_* files are there in the /Applications/PixInsight/src/scripts directory then you just need to go to Scripts > Feature Scripts and click add, then navigate to /Applications/PixInsight/src/scripts and click OK. PI should find the scripts. if for some reason PI finds all of your scripts again and they are all listed twice in the dialog box, click cancel, otherwise all the scripts will be in the menus twice (which is OK, but kind of annoying.)
if that happens then you can delete updates.xri or edit out the EZ script lines from updates.xri, but make a backup copy of updates.xri first. this needs to be done while PI is not running. after that you need to check for updates again and assuming the EZ script repository is still in your list of repositories, it will be downloaded and added to the scripts menu again.
rob