fix command, pyusb is installed with pip, not brew. remove extra ` in command
3. Install the following packages:
```
brew install python
- brew install pyusb
- brew install --HEAD`https://raw.githubusercontent.com/robertgzr/homebrew-tap/master/bootloadhid.rb
+ pip install pyusb
+ brew install --HEAD https://raw.githubusercontent.com/robertgzr/homebrew-tap/master/bootloadhid.rb
4. Place your keyboard into reset.
5. Flash the board by typing `bootloadHID -r` followed by the path to your `.hex` file.