Mercedes Benz repair: Steering Gearbox, seven cycles, bleeder valve

Question
I just replaced the steering gearbox in my 1972 Mercedes 280SE. I need to know how to go about bleeding the gearbox, I don't have a manual.  I tried running the car and allowing the air to escape from the bleeder valve on the gearbox, this helped alittle but the steering is still real stiff.  Any help would be appreciated

Answer
Lift the front end onto jack stands.
Fill the pump, start engine, and rotate the steering wheel full left, then full right, repeat seven cycles.
After seven cycles, turn off engine for thirty minutes, then without starting engine, rotate the steering wheel full left, then full right twice and recheck fluid level.
Start the engine, and rotate the steering wheel full left, then full right, repeat the cycle as needed, checking fluid often.