How to connect a Geeetech Prusa I3 Pro B to Repetier-Host on mac
This is not a direct answer to your question, but a solution for your problem. 

If a motor is running in reverse, there are at least 2 solutions. You can reverse the connector of the leads to the stepper, or flash new firmware where you reverse the stepper in the configuration file. 

The most effective and fast solution is to reverse the connector of rearrange the wires in the connector.