You may have to change a combination of things to get this working right... You'll probably have to reverse the motor direction and switch your endstop to home to max instead of min. I don't actually have this printer, so I can't say for sure... but you can try a few things until you get it working right. Please report back when you do so others can see this post if they run into the same issue.
What it looks like Jam did was reverse the motor direction, then put the min endstop on the other side. You could do that or leave it where it is and change to a max endstop (firmware adjustment and a move wire inside the board from X- to X+).
Depending on the firmware version, you should look for the sections that look something like this:
under homing section:
uncomment the commented one, and comment the uncommented one... e.g., go from this:
// #define use_xmax_plug
// #define use_xmin_plug
to reverse motor direction:
change from this:
#define INVERT_X_DIR false
#define INVERT_X_DIR true
or vice-versa (if it started as true, then switch to false)