Non-Turbo Model

Remove the clip (B) above the air cleaner case.

Fig 1: Removing Clip Air Cleaner Case
Courtesy of SUBARU OF AMERICA, INC.
Remove the air cleaner.

Fig 2: Removing Air Cleaner
Courtesy of SUBARU OF AMERICA, INC.
Install in the reverse order of removal.
NOTE: Align the protruding portion of air cleaner upper cover with holes of air cleaner lower case, then secure upper cover to case.

Fig 3: Aligning Protruding Portion Of Air Cleaner Upper Cover With Holes
Courtesy of SUBARU OF AMERICA, INC.