Depends on the condition of the fluid. Toyota's use Dexron in their power steering system. Normally this looks like red kool-aid or Nyquil. If it is black and dirty, then it needs changed.
Most cars do not need this service until closer to 100,000. However, some cars (the Tc included) do not properly cool the power steering fluid and the fluid overheats, scorches, and turns black.
I would replace the power steering fluid - a flush may not be necessary, just a drain and fill. You can do this yourself in < 30 minutes if you can take off the front passenger side wheel and have a pair of pliers to disconnect the power steering line.
To bleed air from the system - Turn the wheel lock to lock (all the way left, all the way right) and refill the reservoir. Turn the car on and let the air work its way out of the system (5 to 10 min) and refill the resevior. With the enginge running, again turn the wheel lock to lock and refill the resivior. At this point most of the air should be out of the system, if there is still air in the system your steering will be loud(gurgly?) intermittently. You can continue to turn the wheel lock to lock or take a (short) drive around the neighborhood to let any remaining air out.
When you're done, double check the resivior level and look for any leaks.