How to install sub???

I've been searching and searching for a how to on a sub install but cant find anything. Ive got an 08 GSR with the factory nav option but no SSS (dont ask me why it was ordered this way as I'm the second owner). Anyways I'm not very knowledgeable about stereo/speakers but I picked up an all in one kicker sub/amp combo to add a bit of bump to the otherwise flat stock system and I'm looking for some guidance on how to go about installing it. Any help would be much appreciated!