For a quad running any brand of firmware, the motors must either be (assuming LP numbering) CW,CCW,CW,CCW <or> CCW,CW,CCW,CW
In LP, the default is CW,CCW,CW,CCW
In LP to use motors you have set up to be CCW,CW,CCW,CW, you just check the checkbox called "Reverse All Motors" on the Vehicle page.
If you are talking about reversing a single motor to make it fit the required order, you can:
- swap any two of three motor wires
- tell the ESC firmware to run it backwards (there are options for this in BLHeli and SimonK, and some stock ESC firmwares have a "transmitter menu with beeps" where you can do this ... you must have the instructions for that ESC to make changes like this and while you are at it you must disable LowVoltageCutoff or set it to Nicad)
Two wrongs do not make a right. If a motor is running backwards, you can't just put the other kind of prop on it.