Providing there is enough length of wire, simple cut off those connectors and solder directly to the tabs on the motor. As Rudolf says, if you will change the motor a lot, then find some bullets to fit those sockets and solder the bullets to the motor tabs.
The order in which those wires go on the motor is critical - get it wrong and there'll be tears!
The speedo should be labeled A,B,C, and the motor the same. I'm sure you haven't been away so long that I need to say connect A to A, B to B and C to C - but I said it anyway!! Welcome back to the best hobby in the world, and good luck with your new car. HTH
