The only way you could grab the firmware is by dumping the code from the NAND or other storage medium. Like kulver said you would need special tools, and removing the chips aren't going to help. You also need an in-depth knowledge about hardware before even attempting. They also lock down firmware on the hardware level by using fuse bits and other methods, so even attempting to read memory would result in a bricked device.
The only way of doing anything at this point is finding a serial line. But that would require tracing the circuit after finding the ftdi or rs232 chips and hope the left some headers broken out. Then you would need to know the baud rate stop bits and if it used flow control just to even communicate with the bootloader.
The best thing you could do is salvage it for parts. Matrix keypad, tiny motor, speakers, Mic, and LCD screen (would need the driver chip though).
Maybe look into AVR dev if your interested in hardware and embedded systems.
