Here is where it gets tricky... It's highly likely that your connectors will not match -- mine didn't. The best way to go about this is to start with one connector. See if both sides mate. If they do, more on.
If Not - check the other side of the connector on the other scooter. Then remove the pins from the connector and do a Frankenstein swap. The pins usually have a small tap inside - push it to the side with a small screw driver, then pull the wire/pin out.
Sometimes, there's no remedying it. In cases like these -- you can jam the pin on the wire into the connector, then secure with tape. Be sure they won't short inside the tape as these motor controllers are rather sensitive :/
You absolutely need to connect the following items
1. Hall Effect Throttle 2. Motor 3. Battery
For safety you should also connect the brake switch.