Hi, I have this same razor and I replaced the batteries myself. The batteries, if I recall, were about $5.95 a piece from the Battery Barn http://www.batterybarn.com/shaver7.htm. The batteries are soldered onto the circuit board. To get to the circuit board you need to remove two plastic caps on the bottom of the shaver and then remove the phillips head screws. Then remove the bottom part of the shaver to expose the batteries and circuit board. There are two little clear plastic cylinders that side into toward the charge light diodes to magnify them, pull these out gently. Remove the plastic cover over the battery and then gently pull the board out. The batteries are glued to the circuit board. Use an exacto knife to cut under the glue. Then use solder pen to free up each battery's terminal from circuit board. Side new battery terminal through circuit board making sure you have the right polarity, resolder, replace circuit board back into razor. put plastic magnifiers back in place, put plastic cover back in place, put bottom on and tighten screws. Replace plastic caps on bottom.
Larry, Canton, Michigan, March 2010