These pictures should answer your question. If they don’t, look at the Charge Voltage in V (Volts) and mAh (milliAmp hours), and the Nominal Voltage in V (Volts). BOTH OF THESE NUMBERS MUST MATCH! The mAh, however, does not; it simply determines how long it will last, based on Amp hours. I unfortunately don’t have the proper calculations in front of me, but, the higher the number, the better. But, if you look at the pictures, both batteries share the exact same figures, and the exact same charging ports on the corner of the battery. The 903 and 900 are identical, in my eyes.

Probably involves the following tools:

Saudering gun

Hammer

Chisel

There is no pretty way to disassemble these parts for even recycling, I'd imagine.