The below video describes the difference between mode 1 and mode 2;
The mode will swap what the left and right sticks do; mode 1 throttle will be controlled by the left stick and in mode 2 the throttle will be controlled by the right stick.
Selecting mode 1 or mode 2 is the same for the H7000 and FPV1 transmitter.
To select mode 1 from an off state put the left stick to the top left and the right stick to the top right, power on the transmitter and it should boot in mode 1. It will ask you to calibrate the sticks in that mode.
For mode 2 put the left stick in the top left position and the right stick in the top left position then press the power button. When the transmitter powers up it will ask you to calibrate the sticks.
Once the sticks are calibrated check the calibration on the H7000 by going into the menu and on the FPV1 by looking at the reticules on the screen.
Video of putting the FPV1 in mode 2 and checking the stick calibration