1. Download and install the [Teensy Loader](https://www.pjrc.com/teensy/loader.html). Some Linux distributions already provide a binary (may be called `teensy-loader-cli`), so you may prefer to use this.
2. Find a firmware file you like. You can find a few of these in the keymaps subdirectory right here. The file you need ends with .hex, and you can look at its .c counterpart (or its PNG image) to see what you'll be getting. You can also use the [Massdrop configurator](https://keyboard-configurator.massdrop.com/ext/ergodox) to create a firmware Hex file you like.
4. Connect the keyboard, press its Reset button (gently insert a paperclip into the hole in the top-right corner) and flash it using the Teensy loader you installed on step 1 and the firmware you downloaded.
5. Edit this file, changing keycodes to your liking (see "Finding the keycodes you need" below). Try to edit the comments as well, so the "text graphics" represent your layout correctly. See below for more tips on sharing your work.
6. Compile your firmware by running `make keymap=keymap_name`. For example, `make keymap=german`. This will result in a hex file, which will be called `ergodox_ez_keymap_name.hex`, e.g. `ergodox_ez_german.hex`. For **Infinity ErgoDox** you need to add `subproject=infinity` to the make command.
7.**ErgoDox EZ** - Flash this hex file using the [Teensy loader](https://www.pjrc.com/teensy/loader.html) as described in step 4 in the "Easy Way" above. If you prefer you can automatically flash the hex file after successful build by running `make teensy keymap=keymap_name`.
The ErgoDox firmware is open-source, so it would be wonderful to have your contribution! Within a very short time after launching we already amassed almost 20 user-contributed keymaps, with all sorts of creative improvements and tweaks. This is very valuable for people who aren't comfortable coding, but do want to customize their ErgoDox. To make it easy for these people to use your layout, I recommend submitting your PR in the following format.
3.`readme.md` - a readme file, which GitHub would display by default when people go to your directory. Explain what's different about your keymap, what you tweaked or how it works. No specific format to follow, just communicate what you did. :)
4. Any graphics you wish to add. This is absolutely not a must. If you feel like it, you can use [Keyboard Layout Editor](http://keyboard-layout-editor.com) to make something and grab a screenshot, but it's really not a must. If you do have graphics, your readme can just embed the graphic as a link, just like I did with the default layout.
Let's say you want a certain key in your layout to send a colon; to figure out what keycode to use to make it do that, you're going to need `quantum/keymap_common.h`.
