Edit: Z-wave network just needs to be stopped to edit files, below may be incorrect. HA restart may be needed before any changes to edited Z-wave files are picked up.
The terminology can be confusing. HA Add-ons do not shut down when Home Assistant itself is stopped (not shut down). I personally use the Samba add-on to access the files and edit my files with Notepad++, then SSH to bring Home Assistant back up.
So once Samba is all set up and you confirm you have access, you can go to Configuration > Server Controls > Server Management > Stop. Then you can edit OZW files without risking them being over-written before you can save.