you don't need a tutorial for an LOC.. it is one of the simplest devices you will ever hook up. it should include basic instructions that should cover everything. if you buy a used LOC or for some other reason it didn't come with instructions, here are some very basic instructions:
a basic 2-channel LOC has 4 speaker level input wires and 2 line-level RCA outputs. you connect the 4 speaker level input wires to any left/right speaker wires (it doesn't matter if they are front or rear). you will need to figure out which wires are pos/neg; the speaker terminals are often marked, if not then search on google for your car's speaker wire colors (polarity). you will need a set of RCA cables to connect the LOC's line-level outputs to your amp's RCA inputs.
NOTE: if your amp has speaker-level inputs then you don't need an LOC at all. just hook your left/right speaker wires directly up to the amp"s speaker level inputs.