The existing amp/ram stays, the harness plugs into the high level (speaker) output interface on the RAM (the connector plugged into the OEM unit mounted on the black bracket) and the existing speaker interface that was plugged into the RAM now plugs into the match harness (connection in the middle of the wire harness). That is... the Match amp sits between the RAM and the OEM speakers. It intercepts the amplified signal from the OEM amp, converts it to run into the new amp where it's amplified again and pushed out the speakers.
Given you have a hybrid, you need to ensure this setup will work for you. Contact the Audiotech US distributor (Jason Digos -
jason@msc-america.com), many people have been wondering the same thing.