Fill in .env with the variables BOT_TOKEN, APPLICATION_ID and GUILD_ID (optionally, if you want to register guild commands). Then run register-bot-commands.js.
Run register-bot-commands.js and it will register everything in bot-commands.json (which is filled out with all the commands already). delete-bot-commands.js takes every command ID in command-ids.txt (separated by whitespace) and unregisters them.
Both programs default to global application commands, which is what you probably want unless you're debugging. Specify -g as a commandline argument to switch to registering to (or deleting from) a specific server.
Also, fetch was added to NodeJS in v17.5, so don't use any super old Node installs.