charging a capacitor

I bought a Rockford sub and amp off a friend of mine and I'm trying to install it in a 99 Escort. This is my first install and I'm using the OEM radio with no RCA pre-outs, but the amp has line level inputs on it. I wanted to use the existing rear speaker wires rather than running new wires from the HU to the trunk. I can just pull em off the rear speakers and connect em to the amp, right?? That leaves me with 2 front speakers and a sub in the trunk. The OEM radio's fader can be used to adjust the sub level.

I also got a .5 farad capacitor from my buddy. Should this be hooked up in "parallel" with the amp? I saw this on Rockford's technical help site. I also read that I need to charge it before installing. Since I dont have the charging cap/card that usually comes with it, I was gonna use the resister method. They used a 50ohm 1W resister. Should this work for my setup?? I kinda scared of this capacitor!!

The 1st link is to the capacitor install page and the 2nd is about charging it...

http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_sid=&p_lva=&p_faqid=50&p_created=952039877

http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_sid=&p_lva=50&p_faqid=153&p_created=1049433410

Thanks for your help