Subaru 2005 Legacy Owner's Manual page 565

Maintenance and service
4. Align the claws of the plastic support with the
grooves in the blade rubber assembly, then slide the
blade rubber assembly into place.
11-66
Securely retain both ends of the rubber with the stop-
pers on the plastic support ends. If the rubber is not re-
tained properly, the wiper may scratch the rear win-
dow glass.
5. Install the wiper blade assembly to the wiper arm.
Make sure that it locks in place.
6. Hold the wiper arm by hand and slowly lower it in
position.