WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
Remove the engine oil dipstick.
Disconnect the knock sensor 1P connector (A).
Fig 1: Lnock Sensor 1P Connector And Knock Sensor With Torque Specifications
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Remove the knock sensor (B).
Install the parts in the reverse order of removal.