1. Mine cover screws take a Torx T5. Bought a kit with all sizes (plus some other handy tiny electronic tools)on Amazon for $6.00 US.

2. The twisted wires from the back cover to the circuit board may not have a connector. The wire in mine was secured to the circuit board with two molecule-sized spots of solder which, of course, broke loose as soon as I opened the cover, stretching the too-short wire to its limit. I don’t know the funtion of this pair of small, twisted wires. They go from the circuit board to a slit opening in the back cover. Maybe a microphone for the bluetooth?? With no way to re-solder the two barely visible spots, I taped the wire out of the way and closed the unit back up. GPS functions all still work. Haven’t tried the bluetooth…I don’t use it anyway.