There are no quick fixes or DIY on the steering rack.
The rack is one unit, and other than the tie rod ends is not serviceable in any way. This is typical for EPS units, especially ones with a belt driven ball screw (as the Focus has).
The belt has a special process to be tensioned, so anyone who tries to remove the ECU and install a new one on the rack will not tension it correctly and this will lead to failure (improperly tensioned belts can and usually do break).
The only option besides a new unit is a remanufactured unit, but regardless you would need the correct software put on the system by a dealer (or 3rd party who has access to Ford flashing tools).
Outside of that, the only other physical option would be a custom solution where you install a manual rack. This obviously isn't advised as the efforts required would be identical to the ones experienced during manual steering with the failed rack. One could design a system which perhaps has a faster c-factor (rack ratio), but again this is all custom work at this point. Probably easier to just get another stock rack.
