Help W/ JL Slash Amp!

Im getting ready to install a Slash 500/1v2 and a pair of JL 10tw3's in my DC.
Ill be using the stock HU, i know that with the slash amps i wont need a LOC.
So all i have to do is splice into the factory rear speakers with a Speaker cable to RCA Cable correct? also will i have to do left and right or can i just tap into one side?

 

Sub'd I would like to know as well

 

I would still recommend using a Line Output Converter. The Slash v2 does have a high/low input selection switch, but the rated input voltage range has a maximum of 8 volts. I wouldn't risk compromising my gain structure just to save the money for a line output converter.