Update your Flame to B2G OS in 5 easy steps...

0. Get a GNU/Linux (64 bits) distro
1. Grab Firefox Nightly from https://nightly.mozilla.org/
2. Override add-on signing https://support.mozilla.org/kb/add-on-signing-in-firefox#w_override-add-on-signing-advanced-users
3. Get B2G Installer from https://lissyx.github.io/b2g-installer/
4. Go to about:b2g-installer
5. Follow the 3 easy steps there...

If you get stuck, please ask us questions at https://vector.im/develop/#/room/#mozilla_#fxos:matrix.org