You don't even need to download anything - if you're using a supported browser you can just use the web installer (you can even use another Android phone!): https://grapheneos.org/install/web
Any Chromium-based browser works including Edge included with Windows, Brave or our own Vanadium browser. Firefox may be gradually changing their mind about WebUSB. They added similar features they said they wouldn't such as MIDI. We would make some minor changes and test each revision in Firefox if we could, but they don't provide a way to do it.
