"Easy" way is replace FFB 2 handle with one that have neutral design - suitable for left hand use, e.g. CH Flighstick, Tm T.16000M,
Saitek Cyborg... All 4 buttons + HAT like FFB2.
Will be need use the PCB under the FFB2 HAT for wire HAT and switches of new handle, since this PCB had some electrical components - resistors and/or diodes.
Or do a "plastic surgery" in FFB2 handle, cutting of the thumb rest on left side and using Epoxy putty, paint... - this will be more laborious, but don't involve solder, etc.