blimey, must be a first, competition mode enabled
Anyway, it's easy, just open the grip like you were changing the battery, on the board there is a white connector with 4 pins, take a flat head screwdriver and rest it against the middle 2 pins at least (doesn't matter if it's 3 or all 4 though). Don't force it, you are just trying to short the pins not break the board
Then just turn the gun on with the pins shorted, wait for it to boot up, take the screwdriver way and turn it off/on again, that will now be out of competition mode (wont say comp on boot) and the extra options will be there in the menu you used before.
It's dead easy, to get it back in comp mode you just repeat the process.