I dont have any pictures of the interior of the transmitter but it is actually really simple.
unscrew four screws on the back of the transmitter, open the the transmitter slowly and you now see the main board. with four connectors on.
the two in the middle goes to each sticks. switch place on those two and now you have changed the sticks but they are now inverted and upside down.
Close the transmitter and screw all the screws back.
Download the assistant software from dji.com, connect the phantom with the usb cable, start the assistant software, power up the phantom and transmitter. If this is the first time you connect your phantom you maybe need to upgrade the firmware and you do that via the "upgrade button"
Now you press the "basic" button in the software (se picture) press calibration "start" button and move all your sticks in all directions one by one and when you are done press "finish". Now you need to press the buttons on the right of the control axes so it says "REV" (see picture)
Now just shut program down, power down phantom and controller and then power on again and now it should work.