I have '91 Ford Escort and AIWA head unit with 45W RMS output power and I was thinking of getting 6.5'' Pioneer speakers (50W RMS -here) for the front and 5x7'' Pioneer speakers (40W RMS - here ) for the rear. How hard would it be to install them? Best Buy has a deal where you get the second pair for 50% off plus I have a 15% off coupon for car stereo, so both pairs would only cost me $119. You think I could install it myself and save on the installation fees?