PCB Layout -> Schematic

Ive got a USB -> OBD-II reader that has a USB -> Serial chip onboard (FTDI FT232BL). I would like to take the OBD header off, and modify the reader to include a serial port instead. I have the datasheet on the chip, but the methods it shows to connect the chip to a Serial port do not match up with the board. The board uses transistors and a TI LM393P chip, neither of which are mentioned in the datasheet. If I were to disassemble the board down to the bare PCB, would anyone be able to tell me how the transistors and TI chip are used?

Also, any tips for stripping a board with SMT components? I assume a real SMT rework station would be best - is there anything cheap I could use in place of one, or maybe make my own? I remember seeing something about a desoldering tool & aquarium pump - does this sound familiar to anyone?

Some people just use a soft flame from a propane torch or a hot air gun on the back side. Most components fall off or can be flicked off. John

Its double-sided, I wouldnt want to destroy the components on the other side.