Panda,
1. Assemble the sprocket into the housing (just put a bolt with nut loose to hold in position).
2. Tension up spring by turning the sprocket.
3. Put friction spring on and in position.
4. Put the two screws in housing and place the anti bounce bracket into position (the screws will hold it on).
5. Remove the bolt(used to hold in position) and put in screw for holding housing to engine.
6. Fit starter housing to motor.
7. Then pull rope and if the motor is ok it should start and rope will retract back into starter housing.
If this does not work then go to spare parts and manuals area and look for victa manuals Gear Starter for more directions.