The calibration data is different for every wiimote. You'd have to get the wiimote running properly first, then do tests to find the right values and write them to the EEPROM. But that part at least can be done via software.
For the firmware you'd need to use a source dump from the same type of wiimote. You'd need to fix up the MAC addresses, having multiple wiimotes with the same address wouldn't work out too well. I think the best way to proceed would be to dump the damaged firmware before writing anything and compare it to undamaged firmware to try and figure out exactly what's wrong.
For the firmware you'd need to use a source dump from the same type of wiimote. You'd need to fix up the MAC addresses, having multiple wiimotes with the same address wouldn't work out too well. I think the best way to proceed would be to dump the damaged firmware before writing anything and compare it to undamaged firmware to try and figure out exactly what's wrong.