First get the OpenWrt firmware. You need the tftp-recovery file for initial flash, but it is also worth getting the sysupgrade file to use if you ever want (or need) to do a rollback.
You need to run tfpt for flashing the firmware. That is a command line program already on your Mac but a GUI to it makes things easier. There is TftpServer but that site is unreliable so it is likely easier to download from MacUpdate or c|net. There is also Transfer which is commercial software with a 7 day free trial.
- Copy the OpenWrt
tftp-recoveryfile to/private/tftpboot/tp_recovery.bin. - In Terminal run
sudo chmod 777 /private/tftpboot/*. - Start the tftp server using your choice of GUI or command line.
- Connect the ro