WARNING: This page is about a different car, the 2003 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
Install in the reverse order of removal.
Tightening torque:
18 N.m (1.8 kgf-m, 13.0 ft-lb)
Fig 1: Installing Engine Coolant Temperature Sensor In Reverse Order Of Removal