4 Door Model

WARNING: This page is about a different car, the 2015 Subaru XV Crosstrek and 2015 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the ground cable from battery.
Remove the mat - trunk.
Remove the trim panel - trunk rear.
1. Remove the clip.
2. Release the claws, and remove the trim panel - trunk rear.
  
  Fig 1: Locating Trim Panel Clips (Trunk Rear)
  Courtesy of SUBARU OF AMERICA, INC.
Remove the clips, and turn over the trim panel - trunk side.

Fig 2: Locating Trim Panel Clips (Trunk Side)
Courtesy of SUBARU OF AMERICA, INC.
Remove the light assembly - rear combination.
1. Remove the harness clip and connector.
2. Release the nuts and clips, then remove the light assembly - rear combination.
  CAUTION: Be careful not to damage the clips.
  
  Fig 3: Removing Rear Combination Light Assembly
  Courtesy of SUBARU OF AMERICA, INC.