The La Fonera 2.0 (FON 2202) comes with ssh enabled, which isn't a big surprise since it's still in beta and developers are encouraged to develop plugins for the Fonera platform. Even with ssh enabled though, the best way to hack the Fonera, i.e., to replace the currently deployed (very customized) linux distribution with some thing like DD-WRT or OpenWrt, still is directly accessing the bootloader.

Almost exactly like in previous Fonera versions, the bootloader (RedBoot) waits for a few seconds to be interrupted, before moving on and booting the deployed kernel. The Fonera 2.0 will wait at IP address 192.168.1.1 on port 9000, for no more than 2 seconds, to receive an iterrupting Control C. Meaning, if a host computer with an assigned IP of something like 192.168.1.254 is connected to the Fonara, issues this command:

echo -e "\0377\0364\0377\0375\0006" >break.bin; sudo nc -vvv 192.168.1.1 9000 < break.bin; telnet 192.168.1.1 9000

and the Fonera gets rebooted, RedBoot will pause the booting process and show RedBoot> prompt.

If that for whatever reason doesn't work, there is still a way to access and interrupt the bootloader through the internal serial connector, like shown here: Issuing the following command in OS X's Terminal app,
screen /dev/tty.KeySerial1 9600
rebooting the Fonera, and subsequently pressing Control C will also interrupt the boot process and grant access to the bootloader prompt.