Remington pf7400 Comfort Series Foil Shaver and its complete disassembly. How to remove the motherboard that contains the batteries if you are going to replace them. What batteries does the Remington Comfort Series Foil Shaver use and how can they be replaced. If you want to replace the internal batteries, you will need to use a soldering iron and proceed very carefully. Only an experienced person or a service center must always perform this operation. Instructions on how to open and disassemble the internal components, how to assemble the motor and other parts of the Remington shaver. Remington Comfort Series Foil Shaver Teardown