each motor has 2 wires, motor (A) has black and white wires, motor (B) has red and blue wires.
To install, remove the drone propellers and disassemble the drone housing, please remember the position of the wires soldered on the main board and take out the motor that needs to be replaced. Replace the motor with a new one with the corresponding wires, then solder the new motor wires to the main board of the drone, and install the drone housing and propeller back on.